Increment the compiler client pipe name if one already exists
Increment the compiler client pipe name if one already exists

There are certain cases, e.g. when a user elevates their permission
level, when a user would like to use two concurrent compiler servers
started from the same path, but with different processes. Since the
current connection semantics depend on the pipe name being the hash
of the directory containing the client exe, this is not possible.

This change appends an incrementing integer to the requested pipe
name until an available pipe is found, and changes the connection
semantics for the client to search all pipe name variants until an
empty one is found or it has connected.

nagyistoce/roslyn,TyOverby/roslyn,huoxudong125/roslyn,drognanar/roslyn,VSadov/roslyn,managed-commons/roslyn,yjfxfjch/roslyn,weltkante/roslyn,hanu412/roslyn,MatthieuMEZIL/roslyn,khellang/roslyn,krishnarajbb/roslyn,sharwell/roslyn,bbarry/roslyn,genlu/roslyn,taylorjonl/roslyn,wvdd007/roslyn,physhi/roslyn,SeriaWei/roslyn,amcasey/roslyn,evilc0des/roslyn,OmarTawfik/roslyn,jcouv/roslyn,managed-commons/roslyn,ValentinRueda/roslyn,EricArndt/roslyn,antiufo/roslyn,cybernet14/roslyn,VShangxiao/roslyn,davkean/roslyn,akrisiun/roslyn,Maxwe11/roslyn,CaptainHayashi/roslyn,swaroop-sridhar/roslyn,garryforreg/roslyn,AArnott/roslyn,dotnet/roslyn,taylorjonl/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,doconnell565/roslyn,reaction1989/roslyn,natgla/roslyn,YOTOV-LIMITED/roslyn,KevinRansom/roslyn,rgani/roslyn,rchande/roslyn,managed-commons/roslyn,natgla/roslyn,stebet/roslyn,MattWindsor91/roslyn,basoundr/roslyn,shyamnamboodiripad/roslyn,stjeong/roslyn,khyperia/roslyn,nagyistoce/roslyn,leppie/roslyn,cston/roslyn,magicbing/roslyn,Giftednewt/roslyn,KevinH-MS/roslyn,KashishArora/Roslyn,jaredpar/roslyn,abock/roslyn,KevinH-MS/roslyn,DustinCampbell/roslyn,wvdd007/roslyn,krishnarajbb/roslyn,vcsjones/roslyn,sharwell/roslyn,shyamnamboodiripad/roslyn,DinoV/roslyn,vcsjones/roslyn,v-codeel/roslyn,moozzyk/roslyn,mattwar/roslyn,TyOverby/roslyn,Pvlerick/roslyn,a-ctor/roslyn,dotnet/roslyn,stjeong/roslyn,jeffanders/roslyn,nagyistoce/roslyn,pjmagee/roslyn,jkotas/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,ahmedshuhel/roslyn,balajikris/roslyn,drognanar/roslyn,MihaMarkic/roslyn-prank,supriyantomaftuh/roslyn,genlu/roslyn,diryboy/roslyn,KamalRathnayake/roslyn,jcouv/roslyn,AmadeusW/roslyn,a-ctor/roslyn,SeriaWei/roslyn,sharadagrawal/TestProject2,physhi/roslyn,dovzhikova/roslyn,tvand7093/roslyn,gafter/roslyn,rchande/roslyn,zooba/roslyn,jeremymeng/roslyn,a-ctor/roslyn,khyperia/roslyn,basoundr/roslyn,RipCurrent/roslyn,jrharmon/roslyn,tannergooding/roslyn,taylorjonl/roslyn,cybernet14/roslyn,3F/roslyn,ValentinRueda/roslyn,AlekseyTs/roslyn,bartdesmet/roslyn,weltkante/roslyn,HellBrick/roslyn,aanshibudhiraja/Roslyn,kienct89/roslyn,jeremymeng/roslyn,nguerrera/roslyn,oberxon/roslyn,zooba/roslyn,abock/roslyn,ljw1004/roslyn,KevinRansom/roslyn,dpoeschl/roslyn,supriyantomaftuh/roslyn,mgoertz-msft/roslyn,MavenRain/roslyn,thomaslevesque/roslyn,GuilhermeSa/roslyn,orthoxerox/roslyn,stephentoub/roslyn,KashishArora/Roslyn,AlexisArce/roslyn,budcribar/roslyn,mseamari/Stuff,VSadov/roslyn,tang7526/roslyn,HellBrick/roslyn,AdamSpeight2008/roslyn-AdamSpeight2008,sharadagrawal/TestProject2,mavasani/roslyn,lisong521/roslyn,enginekit/roslyn,mmitche/roslyn,lorcanmooney/roslyn,cston/roslyn,khellang/roslyn,drognanar/roslyn,swaroop-sridhar/roslyn,KiloBravoLima/roslyn,bartdesmet/roslyn,magicbing/roslyn,genlu/roslyn,MihaMarkic/roslyn-prank,KiloBravoLima/roslyn,reaction1989/roslyn,DinoV/roslyn,mgoertz-msft/roslyn,aelij/roslyn,mattscheffer/roslyn,tang7526/roslyn,VSadov/roslyn,evilc0des/roslyn,jeffanders/roslyn,oocx/roslyn,antonssonj/roslyn,magicbing/roslyn,KirillOsenkov/roslyn,OmarTawfik/roslyn,cybernet14/roslyn,rgani/roslyn,michalhosala/roslyn,zmaruo/roslyn,lorcanmooney/roslyn,Hosch250/roslyn,FICTURE7/roslyn,droyad/roslyn,evilc0des/roslyn,VPashkov/roslyn,diryboy/roslyn,VShangxiao/roslyn,Inverness/roslyn,Shiney/roslyn,CaptainHayashi/roslyn,jamesqo/roslyn,jmarolf/roslyn,jbhensley/roslyn,v-codeel/roslyn,mattwar/roslyn,physhi/roslyn,jrharmon/roslyn,kelltrick/roslyn,Inverness/roslyn,mirhagk/roslyn,grianggrai/roslyn,chenxizhang/roslyn,DustinCampbell/roslyn,JakeGinnivan/roslyn,kienct89/roslyn,furesoft/roslyn,robinsedlaczek/roslyn,devharis/roslyn,ilyes14/roslyn,aanshibudhiraja/Roslyn,xasx/roslyn,paulvanbrenk/roslyn,agocke/roslyn,dpoeschl/roslyn,stephentoub/roslyn,shyamnamboodiripad/roslyn,michalhosala/roslyn,grianggrai/roslyn,wvdd007/roslyn,ErikSchierboom/roslyn,sharadagrawal/Roslyn,mmitche/roslyn,huoxudong125/roslyn,leppie/roslyn,eriawan/roslyn,akrisiun/roslyn,stjeong/roslyn,xasx/roslyn,enginekit/roslyn,dovzhikova/roslyn,chenxizhang/roslyn,YOTOV-LIMITED/roslyn,gafter/roslyn,KevinH-MS/roslyn,nemec/roslyn,kienct89/roslyn,Shiney/roslyn,ahmedshuhel/roslyn,pjmagee/roslyn,vslsnap/roslyn,RipCurrent/roslyn,tmeschter/roslyn,heejaechang/roslyn,furesoft/roslyn,AlekseyTs/roslyn,jroggeman/roslyn,poizan42/roslyn,CyrusNajmabadi/roslyn,poizan42/roslyn,dotnet/roslyn,ericfe-ms/roslyn,srivatsn/roslyn,jeffanders/roslyn,droyad/roslyn,ValentinRueda/roslyn,jaredpar/roslyn,jroggeman/roslyn,orthoxerox/roslyn,ErikSchierboom/roslyn,brettfo/roslyn,akrisiun/roslyn,orthoxerox/roslyn,zooba/roslyn,xoofx/roslyn,MattWindsor91/roslyn,jasonmalinowski/roslyn,KirillOsenkov/roslyn,DustinCampbell/roslyn,VShangxiao/roslyn,agocke/roslyn,FICTURE7/roslyn,tmat/roslyn,heejaechang/roslyn,EricArndt/roslyn,aelij/roslyn,ljw1004/roslyn,natidea/roslyn,budcribar/roslyn,panopticoncentral/roslyn,JakeGinnivan/roslyn,Giftednewt/roslyn,yeaicc/roslyn,VPashkov/roslyn,brettfo/roslyn,khyperia/roslyn,MavenRain/roslyn,tmeschter/roslyn,natidea/roslyn,agocke/roslyn,Giftednewt/roslyn,sharadagrawal/Roslyn,AArnott/roslyn,russpowers/roslyn,OmniSharp/roslyn,reaction1989/roslyn,MatthieuMEZIL/roslyn,tang7526/roslyn,BugraC/roslyn,KevinRansom/roslyn,oberxon/roslyn,KiloBravoLima/roslyn,mattscheffer/roslyn,paladique/roslyn,JakeGinnivan/roslyn,stephentoub/roslyn,KamalRathnayake/roslyn,VitalyTVA/roslyn,sharwell/roslyn,jcouv/roslyn,tmat/roslyn,MattWindsor91/roslyn,danielcweber/roslyn,Maxwe11/roslyn,leppie/roslyn,ahmedshuhel/roslyn,tsdl2013/roslyn,antonssonj/roslyn,jkotas/roslyn,russpowers/roslyn,KashishArora/Roslyn,moozzyk/roslyn,robinsedlaczek/roslyn,tvand7093/roslyn,MattWindsor91/roslyn,jmarolf/roslyn,jasonmalinowski/roslyn,AlexisArce/roslyn,robinsedlaczek/roslyn,REALTOBIZ/roslyn,panopticoncentral/roslyn,thomaslevesque/roslyn,jonatassaraiva/roslyn,ErikSchierboom/roslyn,xasx/roslyn,zmaruo/roslyn,oberxon/roslyn,MichalStrehovsky/roslyn,DinoV/roslyn,mirhagk/roslyn,jonatassaraiva/roslyn,michalhosala/roslyn,YOTOV-LIMITED/roslyn,krishnarajbb/roslyn,vslsnap/roslyn,mmitche/roslyn,jhendrixMSFT/roslyn,balajikris/roslyn,AlexisArce/roslyn,AlekseyTs/roslyn,budcribar/roslyn,panopticoncentral/roslyn,lisong521/roslyn,CyrusNajmabadi/roslyn,nemec/roslyn,CyrusNajmabadi/roslyn,xoofx/roslyn,khellang/roslyn,OmniSharp/roslyn,hanu412/roslyn,SeriaWei/roslyn,jbhensley/roslyn,pdelvo/roslyn,ilyes14/roslyn,AmadeusW/roslyn,OmniSharp/roslyn,sharadagrawal/Roslyn,garryforreg/roslyn,MavenRain/roslyn,HellBrick/roslyn,cston/roslyn,RipCurrent/roslyn,stebet/roslyn,russpowers/roslyn,VPashkov/roslyn,aelij/roslyn,mirhagk/roslyn,supriyantomaftuh/roslyn,jaredpar/roslyn,GuilhermeSa/roslyn,BugraC/roslyn,bbarry/roslyn,thomaslevesque/roslyn,mattscheffer/roslyn,jonatassaraiva/roslyn,KamalRathnayake/roslyn,antiufo/roslyn,yeaicc/roslyn,Giten2004/roslyn,tsdl2013/roslyn,nguerrera/roslyn,kelltrick/roslyn,srivatsn/roslyn,natgla/roslyn,GuilhermeSa/roslyn,Hosch250/roslyn,moozzyk/roslyn,yeaicc/roslyn,MihaMarkic/roslyn-prank,paladique/roslyn,bkoelman/roslyn,garryforreg/roslyn,antiufo/roslyn,Maxwe11/roslyn,yjfxfjch/roslyn,pdelvo/roslyn,lorcanmooney/roslyn,devharis/roslyn,jeremymeng/roslyn,abock/roslyn,aanshibudhiraja/Roslyn,ljw1004/roslyn,VitalyTVA/roslyn,mseamari/Stuff,kuhlenh/roslyn,Pvlerick/roslyn,bkoelman/roslyn,CaptainHayashi/roslyn,KirillOsenkov/roslyn,paulvanbrenk/roslyn,jrharmon/roslyn,AArnott/roslyn,oocx/roslyn,gafter/roslyn,MichalStrehovsky/roslyn,xoofx/roslyn,mattwar/roslyn,AnthonyDGreen/roslyn,paladique/roslyn,enginekit/roslyn,3F/roslyn,mavasani/roslyn,natidea/roslyn,hanu412/roslyn,doconnell565/roslyn,eriawan/roslyn,oocx/roslyn,kelltrick/roslyn,OmarTawfik/roslyn,davkean/roslyn,tannergooding/roslyn,nemec/roslyn,jbhensley/roslyn,Hosch250/roslyn,rchande/roslyn,brettfo/roslyn,tsdl2013/roslyn,danielcweber/roslyn,jamesqo/roslyn,jroggeman/roslyn,yjfxfjch/roslyn,DanielRosenwasser/roslyn,dovzhikova/roslyn,jmarolf/roslyn,REALTOBIZ/roslyn,ilyes14/roslyn,davkean/roslyn,vslsnap/roslyn,ericfe-ms/roslyn,TyOverby/roslyn,3F/roslyn,huoxudong125/roslyn,BugraC/roslyn,furesoft/roslyn,v-codeel/roslyn,basoundr/roslyn,AmadeusW/roslyn,paulvanbrenk/roslyn,eriawan/roslyn,DanielRosenwasser/roslyn,dpoeschl/roslyn,heejaechang/roslyn,kuhlenh/roslyn,danielcweber/roslyn,amcasey/roslyn,Giten2004/roslyn,vcsjones/roslyn,swaroop-sridhar/roslyn,chenxizhang/roslyn,jhendrixMSFT/roslyn,lisong521/roslyn,amcasey/roslyn,jhendrixMSFT/roslyn,pjmagee/roslyn,diryboy/roslyn,Inverness/roslyn,DanielRosenwasser/roslyn,jasonmalinowski/roslyn,EricArndt/roslyn,grianggrai/roslyn,AnthonyDGreen/roslyn,MichalStrehovsky/roslyn,ericfe-ms/roslyn,jkotas/roslyn,poizan42/roslyn,AnthonyDGreen/roslyn,sharadagrawal/TestProject2,tmeschter/roslyn,mavasani/roslyn,bartdesmet/roslyn,rgani/roslyn,srivatsn/roslyn,mseamari/Stuff,mgoertz-msft/roslyn,pdelvo/roslyn,bbarry/roslyn,weltkante/roslyn,nguerrera/roslyn,Pvlerick/roslyn,stebet/roslyn,Shiney/roslyn,kuhlenh/roslyn,zmaruo/roslyn,tvand7093/roslyn,droyad/roslyn,doconnell565/roslyn,MatthieuMEZIL/roslyn,jamesqo/roslyn,Giten2004/roslyn,devharis/roslyn,balajikris/roslyn,tannergooding/roslyn,VitalyTVA/roslyn,bkoelman/roslyn,tmat/roslyn,antonssonj/roslyn,REALTOBIZ/roslyn,FICTURE7/roslyn