os/exec: document that Cmd.Wait waits for stdin I/O
os/exec: document that Cmd.Wait waits for stdin I/O

Fixes #10338.

Change-Id: Ib86cb9a6c694b1e442a9957153c7ca38a7d11c3e
Reviewed-on: https://go-review.googlesource.com/12232
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

Samurais/go,jdeng/go,alex-zhang/go,leeric92/go,myPublicGit/go,Stan-Lin-/go,jonathanmarvens/go,agaurav/go,jdeng/go,xiuzhifu/go,linux-on-ibm-z/go,jonahglover/go,arschles/go-1,AALEKH/go,arschles/go-1,vishsingh/go,slavau/go,zcwfeng/go,dgnorton/go,9618211/go,yasarkunduz/go,PoohSunny/go,xiuzhifu/go,jefby/go,derekmarcotte/go,vanloswang/go,codestation/go,theass/go,wangfakang/go-1,dgnorton/go,xinhuang327/go,shines77/go,4ad/go,sndnvaps/go,samanalysis/go,rentongzhang/go,zouchao2010/go,mgyenik/go,mgyenik/go,xiaobodu/go,yangzhongj/go,mgyenik/go,9618211/go,jmptrader/go,royels/go,joshsammut/go,danielsoro/go,cloudrain21/go,cookerzhu/go,AALEKH/go,akutz/go,uileyar/go,wangfakang/go-1,yangzhongj/go,devpadawan/go,slavau/go,dafyddcrosby/go,Young55555/go,stormltf/go,4ad/go,mikekap/go,vsekhar/elastic-go,vsdutka/go,momchil-velikov/go,mwhudson/go,CAFxX/go,ericsnowcurrently/go,xiaobodu/go,theass/go,jacobxk/go,Jordanzuo/go,mikekap/go,malvira/go,RBEGamer/go,stormltf/go,andrewchambers/go,dkolbly/go,beealone/go,binarycrusader/go,ericsnowcurrently/go,shishkander/go,andrewchambers/go,dafyddcrosby/go,RBEGamer/go,zhangg/go,xujianhai/go,baiyunping333/go,royels/go,arschles/golang-go,dgnorton/go,constantine001/go,cookerzhu/go,willjunspecial/go,constantine001/go,XuYunnan/go,jdhenke/go,shazow/go,Pulgafree/go,sosop/go,jefby/go,ganboing/go-esx,samanalysis/go,Stan-Lin-/go,beealone/go,gohin/go,xinhuang327/go,likesea/go,jonasi/go,zouchao2010/go,miolini/go,beealone/go,arschles/golang-go,alex-zhang/go,NichoZhang/go,chinanjjohn2012/go,Cofyc/go,ifagnosticism/go,shazow/go,snowsnail/go,linux-on-ibm-z/go,ifagnosticism/go,miolini/go,dterei/go,jacobxk/go,Badredapple/go,greyhwndz/go,Samurais/go,arschles/go-1,vsekhar/elastic-go,dkolbly/go,ObjectiveJoe/go,leeric92/go,roth1002/go,NichoZhang/go,odeke-em/go,odeke-em/go,dkolbly/go,Badredapple/go,cyberroadie/go,monetate/go,ichu501/go,akutz/go,goodlang/good,myPublicGit/go,WIZARD-CXY/go,sndnvaps/go,josharian/go,mdp/go,mdp/go,danycoro/go,vsdutka/go,xujianhai/go,youprofit/go,theif519/go,rentongzhang/go,b54898533/go,nawawi/go,yuhengye/go,jonahglover/go,yangzhongj/go,mbrukman/go,chinanjjohn2012/go,qskycolor/go,andrewchambers/go,baiyunping333/go,alash3al/go,mikekap/go,vanloswang/go,alex-zhang/go,sosop/go,undergrowthlinear/go,Charlesdong/go-1,Samurais/go,ganboing/go-esx,4ad/go,ericsnowcurrently/go,ganboing/go-esx,skotti/go,CiscoCloud/go,JioCloud/go,jacobhaven/go,skatsuta/go,qskycolor/go,willjunspecial/go,wangfakang/go-1,agaurav/go,zouchao2010/go,shishkander/go,mbrukman/go,vsekhar/elastic-go,CiscoCloud/go,honsiorovskyi/go,cyberroadie/go,derekmarcotte/go,polyverse-security/go,willjunspecial/go,gdey/go,royels/go,jonathanmarvens/go,youprofit/go,zouchao2010/go,deft-code/go,jameskumar/go,cnbin/go,rachtsingh/gogojuice,akutz/go,uileyar/go,NichoZhang/go,shazow/go,samanalysis/go,jmptrader/go,lihuanghai/go,leeric92/go,samanalysis/go,greyhwndz/go,alex-zhang/go,danielsoro/go,ImJasonH/go,xujianhai/go,Cofyc/go,youprofit/go,leeric92/go,arschles/golang-go,jefby/go,famorted/go,pgmreddy/go,gohin/go,nakedgc/go,youprofit/go,mwhudson/go,sosop/go,greyhwndz/go,WIZARD-CXY/go,linux-on-ibm-z/go,rentongzhang/go,leeric92/go,likesea/go,NunoEdgarGub1/go,CAFxX/go,sinuos/go,CAFxX/go,rentongzhang/go,Jordanzuo/go,samanalysis/go,vsekhar/elastic-go,donnel6809/go,binarycrusader/go,GeorgiCodes/go,slavau/go,Charlesdong/go-1,cloudrain21/go,josharian/go,donnel6809/go,jacobsa/go,dpatel06/go,xiaobodu/go,yasarkunduz/go,NichoZhang/go,fjballest/golang,jacobxk/go,ganboing/go-esx,mbrukman/go,xinhuang327/go,derekmarcotte/go,suncycheng/go,dafyddcrosby/go,zhangg/go,jdhenke/go,danielsoro/go,vishsingh/go,codestation/go,gohin/go,cainiaocome/go,sinuos/go,kevinc0825/go,slavau/go,dafyddcrosby/go,sosop/go,CarterTsai/go,parkdy/go,ImJasonH/go,lihuanghai/go,xinhuang327/go,miolini/go,jonahglover/go,vishsingh/go,codestation/go,Endika/go,CAFxX/go,willjunspecial/go,honsiorovskyi/go,famorted/go,arschles/golang-go,jacobxk/go,joshsammut/go,danielsoro/go,xujianhai/go,Endika/go,CAFxX/go,ErikDubbelboer/go,mikekap/go,momchil-velikov/go,jacobhaven/go,skatsuta/go,XuYunnan/go,fjballest/golang,albertjin/golang-go,ImJasonH/go,cyberroadie/go,donnel6809/go,akutz/go,jacobhaven/go,pgmreddy/go,WIZARD-CXY/go,deft-code/go,stormltf/go,josharian/go,jefby/go,Young55555/go,RBEGamer/go,akutz/go,weisd/go,cainiaocome/go,yasarkunduz/go,cainiaocome/go,kim-racktop/go,dpatel06/go,golang/go,GeorgiCodes/go,NichoZhang/go,jacobxk/go,b54898533/go,goodlang/good,youprofit/go,cloudflare/go,suncycheng/go,ericsnowcurrently/go,gdey/go,ichu501/go,ErikDubbelboer/go,nawawi/go,AALEKH/go,cainiaocome/go,b54898533/go,honsiorovskyi/go,cloudrain21/go,Young55555/go,ErikDubbelboer/go,beealone/go,jacobsa/go,danielsoro/go,CarterTsai/go,slavau/go,nawawi/go,Charlesdong/go-1,josharian/go,zouchao2010/go,theif519/go,pgmreddy/go,dterei/go,dafyddcrosby/go,agaurav/go,leeric92/go,devpadawan/go,monetate/go,nawawi/go,theass/go,jonahglover/go,kim-racktop/go,jmptrader/go,wangfakang/go-1,wangfakang/go-1,honsiorovskyi/go,skotti/go,9618211/go,monetate/go,NunoEdgarGub1/go,undergrowthlinear/go,vanloswang/go,donnel6809/go,alash3al/go,vishsingh/go,Badredapple/go,goodlang/good,alash3al/go,suncycheng/go,sinuos/go,myPublicGit/go,suncycheng/go,famorted/go,cnbin/go,JioCloud/go,miolini/go,derekmarcotte/go,agaurav/go,skatsuta/go,deft-code/go,theif519/go,xiuzhifu/go,CiscoCloud/go,snowsnail/go,vsekhar/elastic-go,yeyuguo/go,akutz/go,cloudflare/go,youprofit/go,vishsingh/go,JioCloud/go,golang/go,ichu501/go,mikekap/go,myPublicGit/go,weisd/go,danycoro/go,odeke-em/go,ImJasonH/go,JioCloud/go,kevinc0825/go,arschles/golang-go,cainiaocome/go,deft-code/go,binarycrusader/go,Stan-Lin-/go,RBEGamer/go,baiyunping333/go,myPublicGit/go,polyverse-security/go,rentongzhang/go,momchil-velikov/go,AALEKH/go,honsiorovskyi/go,jacobhaven/go,Young55555/go,jameskumar/go,springning/go,skatsuta/go,kakuhiroshi/go,pgmreddy/go,parkdy/go,vsdutka/go,jacobsa/go,ErikDubbelboer/go,chinanjjohn2012/go,jonasi/go,xujianhai/go,Samurais/go,devpadawan/go,wangfakang/go-1,cnbin/go,jonasi/go,constantine001/go,cloudrain21/go,nawawi/go,sinuos/go,CarterTsai/go,snowsnail/go,miolini/go,qskycolor/go,Cofyc/go,cloudflare/go,CodyGuo/go,danielsoro/go,sosop/go,yasarkunduz/go,monetate/go,jacobhaven/go,dpatel06/go,uileyar/go,famorted/go,xujianhai/go,WIZARD-CXY/go,mdp/go,binarycrusader/go,andrewchambers/go,mwhudson/go,PoohSunny/go,christopher-henderson/Go,nawawi/go,jacobsa/go,jonahglover/go,likesea/go,lihuanghai/go,jasonxiong/go,shishkander/go,danycoro/go,springning/go,Stan-Lin-/go,jdhenke/go,malvira/go,jacobsa/go,ifagnosticism/go,theass/go,mgyenik/go,yuhengye/go,rachtsingh/gogojuice,mdp/go,ObjectiveJoe/go,skatsuta/go,shazow/go,shishkander/go,fjballest/golang,PoohSunny/go,akutz/go,dterei/go,Cofyc/go,cyberroadie/go,agaurav/go,ImJasonH/go,danycoro/go,cyberroadie/go,monetate/go,Young55555/go,dpatel06/go,agaurav/go,andrewchambers/go,yangzhongj/go,ichu501/go,fjballest/golang,alash3al/go,jonasi/go,zcwfeng/go,sinuos/go,Jordanzuo/go,uileyar/go,skatsuta/go,dpatel06/go,Endika/go,snowsnail/go,arschles/go-1,derekmarcotte/go,xiaobodu/go,b54898533/go,nakedgc/go,linux-on-ibm-z/go,jonathanmarvens/go,Pulgafree/go,alash3al/go,donnel6809/go,RBEGamer/go,Young55555/go,constantine001/go,dkolbly/go,g522342435/go,kim-racktop/go,danycoro/go,jmptrader/go,kakuhiroshi/go,ObjectiveJoe/go,suncycheng/go,rentongzhang/go,royels/go,gohin/go,cnbin/go,jasonxiong/go,baiyunping333/go,PoohSunny/go,alex-zhang/go,nakedgc/go,arschles/golang-go,goodlang/good,miolini/go,ErikDubbelboer/go,Pulgafree/go,leeric92/go,alex-zhang/go,jmptrader/go,linux-on-ibm-z/go,zcwfeng/go,Jordanzuo/go,Jordanzuo/go,xiaobodu/go,XuYunnan/go,ericsnowcurrently/go,Jordanzuo/go,Charlesdong/go-1,mgyenik/go,dafyddcrosby/go,mwhudson/go,gdey/go,samanalysis/go,jonathanmarvens/go,Endika/go,kim-racktop/go,RBEGamer/go,nakedgc/go,theif519/go,fjballest/golang,JioCloud/go,jacobhaven/go,kim-racktop/go,skotti/go,jacobxk/go,yuhengye/go,jasonxiong/go,polyverse-security/go,willjunspecial/go,samanalysis/go,zhangg/go,nawawi/go,devpadawan/go,parkdy/go,sndnvaps/go,jdeng/go,linux-on-ibm-z/go,kevinc0825/go,b54898533/go,cookerzhu/go,goodlang/good,cloudflare/go,constantine001/go,greyhwndz/go,qskycolor/go,yuhengye/go,9618211/go,jdhenke/go,XuYunnan/go,sndnvaps/go,nakedgc/go,myPublicGit/go,skotti/go,danielsoro/go,kevinc0825/go,CodyGuo/go,dgnorton/go,stormltf/go,fjballest/golang,zhangg/go,yeyuguo/go,rachtsingh/gogojuice,likesea/go,codestation/go,akutz/go,GeorgiCodes/go,skotti/go,jdeng/go,Badredapple/go,rentongzhang/go,youprofit/go,cyberroadie/go,josharian/go,baiyunping333/go,CodyGuo/go,theif519/go,lihuanghai/go,deft-code/go,4ad/go,cloudflare/go,gdey/go,rachtsingh/gogojuice,dpatel06/go,xiuzhifu/go,undergrowthlinear/go,albertjin/golang-go,ObjectiveJoe/go,danycoro/go,qskycolor/go,famorted/go,ericsnowcurrently/go,goodlang/good,NunoEdgarGub1/go,NunoEdgarGub1/go,4ad/go,rachtsingh/gogojuice,cainiaocome/go,undergrowthlinear/go,jameskumar/go,monetate/go,roth1002/go,dpatel06/go,Endika/go,jameskumar/go,yasarkunduz/go,gdey/go,springning/go,polyverse-security/go,sndnvaps/go,zhangg/go,weisd/go,yangzhongj/go,youprofit/go,cloudrain21/go,CAFxX/go,b54898533/go,golang/go,mbrukman/go,linux-on-ibm-z/go,snowsnail/go,sndnvaps/go,likesea/go,myPublicGit/go,golang/go,ganboing/go-esx,uileyar/go,NichoZhang/go,yeyuguo/go,jmptrader/go,NichoZhang/go,XuYunnan/go,GeorgiCodes/go,yasarkunduz/go,zouchao2010/go,parkdy/go,Pulgafree/go,XuYunnan/go,ericsnowcurrently/go,nakedgc/go,PoohSunny/go,sosop/go,9618211/go,CAFxX/go,ganboing/go-esx,cloudrain21/go,greyhwndz/go,cainiaocome/go,josharian/go,parkdy/go,PoohSunny/go,yasarkunduz/go,honsiorovskyi/go,kakuhiroshi/go,myPublicGit/go,ericsnowcurrently/go,shishkander/go,Endika/go,alex-zhang/go,xinhuang327/go,jasonxiong/go,yuhengye/go,yasarkunduz/go,nakedgc/go,zcwfeng/go,jasonxiong/go,gohin/go,yangzhongj/go,gohin/go,Pulgafree/go,jacobsa/go,rachtsingh/gogojuice,vishsingh/go,zcwfeng/go,malvira/go,gdey/go,vsdutka/go,monetate/go,roth1002/go,derekmarcotte/go,jameskumar/go,jonasi/go,danielsoro/go,GeorgiCodes/go,mwhudson/go,jacobsa/go,malvira/go,yeyuguo/go,vsekhar/elastic-go,codestation/go,joshsammut/go,leeric92/go,AALEKH/go,Cofyc/go,xiuzhifu/go,albertjin/golang-go,arschles/go-1,cloudflare/go,parkdy/go,shazow/go,jasonxiong/go,vanloswang/go,Stan-Lin-/go,shines77/go,codestation/go,royels/go,xiuzhifu/go,chinanjjohn2012/go,beealone/go,cnbin/go,g522342435/go,Badredapple/go,odeke-em/go,josharian/go,Cofyc/go,skatsuta/go,WIZARD-CXY/go,stormltf/go,Stan-Lin-/go,lihuanghai/go,kakuhiroshi/go,snowsnail/go,miolini/go,CiscoCloud/go,jmptrader/go,polyverse-security/go,cloudrain21/go,greyhwndz/go,roth1002/go,donnel6809/go,shazow/go,jdhenke/go,RBEGamer/go,kevinc0825/go,xiaobodu/go,golang/go,mwhudson/go,mgyenik/go,danycoro/go,jacobhaven/go,momchil-velikov/go,Charlesdong/go-1,monetate/go,AALEKH/go,joshsammut/go,Badredapple/go,roth1002/go,dterei/go,roth1002/go,honsiorovskyi/go,goodlang/good,jasonxiong/go,polyverse-security/go,qskycolor/go,shazow/go,9618211/go,willjunspecial/go,kevinc0825/go,Cofyc/go,skatsuta/go,ichu501/go,mwhudson/go,undergrowthlinear/go,albertjin/golang-go,pgmreddy/go,deft-code/go,rachtsingh/gogojuice,ifagnosticism/go,CiscoCloud/go,NunoEdgarGub1/go,wangfakang/go-1,beealone/go,dgnorton/go,deft-code/go,nakedgc/go,xiuzhifu/go,weisd/go,shines77/go,Cofyc/go,odeke-em/go,theass/go,agaurav/go,jonasi/go,vishsingh/go,golang/go,g522342435/go,zcwfeng/go,AALEKH/go,cyberroadie/go,ErikDubbelboer/go,b54898533/go,dgnorton/go,roth1002/go,fjballest/golang,PoohSunny/go,joshsammut/go,jdeng/go,xiuzhifu/go,mikekap/go,ImJasonH/go,slavau/go,fjballest/golang,cnbin/go,codestation/go,vanloswang/go,CarterTsai/go,b54898533/go,WIZARD-CXY/go,skotti/go,xiaobodu/go,momchil-velikov/go,baiyunping333/go,shishkander/go,famorted/go,Badredapple/go,jameskumar/go,mikekap/go,likesea/go,Badredapple/go,jmptrader/go,springning/go,theass/go,jefby/go,vanloswang/go,theif519/go,kakuhiroshi/go,snowsnail/go,chinanjjohn2012/go,andrewchambers/go,golang/go,dterei/go,cloudflare/go,Samurais/go,golang/go,malvira/go,undergrowthlinear/go,donnel6809/go,WIZARD-CXY/go,JioCloud/go,ObjectiveJoe/go,nawawi/go,josharian/go,vsekhar/elastic-go,albertjin/golang-go,undergrowthlinear/go,odeke-em/go,famorted/go,mgyenik/go,dterei/go,g522342435/go,CarterTsai/go,momchil-velikov/go,alash3al/go,constantine001/go,slavau/go,albertjin/golang-go,theif519/go,ifagnosticism/go,JioCloud/go,mwhudson/go,zouchao2010/go,royels/go,Young55555/go,likesea/go,Samurais/go,zhangg/go,gohin/go,willjunspecial/go,XuYunnan/go,jdhenke/go,gdey/go,jonathanmarvens/go,mdp/go,xinhuang327/go,CAFxX/go,ifagnosticism/go,JioCloud/go,ObjectiveJoe/go,jonahglover/go,snowsnail/go,Young55555/go,WIZARD-CXY/go,CodyGuo/go,cookerzhu/go,constantine001/go,derekmarcotte/go,springning/go,malvira/go,cookerzhu/go,shines77/go,alash3al/go,theass/go,cloudrain21/go,jdeng/go,RBEGamer/go,jonahglover/go,springning/go,chinanjjohn2012/go,rentongzhang/go,ichu501/go,jefby/go,weisd/go,mgyenik/go,mbrukman/go,uileyar/go,skotti/go,stormltf/go,uileyar/go,stormltf/go,mbrukman/go,ErikDubbelboer/go,jasonxiong/go,cnbin/go,Pulgafree/go,devpadawan/go,cnbin/go,binarycrusader/go,jefby/go,samanalysis/go,vanloswang/go,malvira/go,likesea/go,4ad/go,ifagnosticism/go,g522342435/go,dafyddcrosby/go,Charlesdong/go-1,sosop/go,andrewchambers/go,weisd/go,yangzhongj/go,jacobhaven/go,polyverse-security/go,mbrukman/go,GeorgiCodes/go,vanloswang/go,vsdutka/go,ImJasonH/go,qskycolor/go,greyhwndz/go,lihuanghai/go,jonathanmarvens/go,dpatel06/go,CiscoCloud/go,albertjin/golang-go,Pulgafree/go,stormltf/go,alex-zhang/go,dgnorton/go,NunoEdgarGub1/go,beealone/go,theass/go,dkolbly/go,pgmreddy/go,polyverse-security/go,xinhuang327/go,miolini/go,xiaobodu/go,Jordanzuo/go,suncycheng/go,vishsingh/go,kakuhiroshi/go,mdp/go,Endika/go,sosop/go,devpadawan/go,zcwfeng/go,skotti/go,jameskumar/go,dafyddcrosby/go,9618211/go,danycoro/go,roth1002/go,kakuhiroshi/go,joshsammut/go,jacobxk/go,lihuanghai/go,kim-racktop/go,chinanjjohn2012/go,royels/go,codestation/go,shines77/go,shishkander/go,jonathanmarvens/go,cyberroadie/go,baiyunping333/go,chinanjjohn2012/go,cookerzhu/go,weisd/go,yuhengye/go,alash3al/go,jdhenke/go,cloudflare/go,jdeng/go,ichu501/go,kevinc0825/go,weisd/go,goodlang/good,mbrukman/go,jdeng/go,momchil-velikov/go,shazow/go,CiscoCloud/go,Samurais/go,arschles/golang-go,yeyuguo/go,springning/go,GeorgiCodes/go,kim-racktop/go,sinuos/go,baiyunping333/go,albertjin/golang-go,jacobsa/go,zhangg/go,Stan-Lin-/go,pgmreddy/go,zouchao2010/go,cookerzhu/go,jonasi/go,dkolbly/go,parkdy/go,ObjectiveJoe/go,dkolbly/go,jacobxk/go,g522342435/go,greyhwndz/go,9618211/go,ichu501/go,dterei/go,yuhengye/go,CodyGuo/go,sinuos/go,xujianhai/go,xujianhai/go,honsiorovskyi/go,sinuos/go,jefby/go,famorted/go,constantine001/go,4ad/go,deft-code/go,willjunspecial/go,odeke-em/go,CodyGuo/go,uileyar/go,gdey/go,joshsammut/go,yuhengye/go,g522342435/go,suncycheng/go,vsekhar/elastic-go,shines77/go,devpadawan/go,lihuanghai/go,yangzhongj/go,qskycolor/go,ifagnosticism/go,kevinc0825/go,CarterTsai/go,yeyuguo/go,agaurav/go,dkolbly/go,vsdutka/go,g522342435/go,Stan-Lin-/go,zhangg/go,arschles/go-1,arschles/go-1,CarterTsai/go,jonasi/go,cainiaocome/go,parkdy/go,dgnorton/go,NunoEdgarGub1/go,PoohSunny/go,kim-racktop/go,wangfakang/go-1,ImJasonH/go,sndnvaps/go,Jordanzuo/go,mdp/go,4ad/go,CodyGuo/go,ErikDubbelboer/go,yeyuguo/go,linux-on-ibm-z/go,malvira/go,shines77/go,shishkander/go,XuYunnan/go,jonahglover/go,jonathanmarvens/go,AALEKH/go,Charlesdong/go-1,springning/go,zcwfeng/go,rachtsingh/gogojuice,momchil-velikov/go,GeorgiCodes/go,xinhuang327/go,binarycrusader/go,CarterTsai/go,Pulgafree/go,suncycheng/go,slavau/go,binarycrusader/go,mikekap/go,shines77/go,NichoZhang/go,ganboing/go-esx,dterei/go,CiscoCloud/go,royels/go,vsdutka/go,ganboing/go-esx,arschles/golang-go,kakuhiroshi/go,odeke-em/go,devpadawan/go,NunoEdgarGub1/go,andrewchambers/go,gohin/go,derekmarcotte/go,joshsammut/go,jameskumar/go,Endika/go,binarycrusader/go,jdhenke/go,sndnvaps/go,arschles/go-1,Samurais/go,theif519/go,undergrowthlinear/go,beealone/go,ObjectiveJoe/go,cookerzhu/go,mdp/go,donnel6809/go,vsdutka/go,CodyGuo/go,pgmreddy/go,yeyuguo/go,Charlesdong/go-1