runtime: document gctrace format
runtime: document gctrace format

Fixes #10348.

Change-Id: I3eea9738e3f6fdc1998d04a601dc9b556dd2db72
Reviewed-on: https://go-review.googlesource.com/12453
Reviewed-by: Russ Cox <5ad239cb8a44f659eaaee0aa1ea5b94947abe557@golang.org>

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