Revert compiler update that slowed down the build
Revert compiler update that slowed down the build

This restores the compiler toolset from prior to #41575 to mitigate the
build performance regression.

weltkante/roslyn,davkean/roslyn,shyamnamboodiripad/roslyn,weltkante/roslyn,shyamnamboodiripad/roslyn,eriawan/roslyn,brettfo/roslyn,panopticoncentral/roslyn,AlekseyTs/roslyn,diryboy/roslyn,genlu/roslyn,tmat/roslyn,aelij/roslyn,brettfo/roslyn,physhi/roslyn,mgoertz-msft/roslyn,KirillOsenkov/roslyn,genlu/roslyn,physhi/roslyn,sharwell/roslyn,dotnet/roslyn,KevinRansom/roslyn,gafter/roslyn,CyrusNajmabadi/roslyn,reaction1989/roslyn,heejaechang/roslyn,aelij/roslyn,eriawan/roslyn,abock/roslyn,genlu/roslyn,AmadeusW/roslyn,davkean/roslyn,weltkante/roslyn,reaction1989/roslyn,panopticoncentral/roslyn,abock/roslyn,eriawan/roslyn,jmarolf/roslyn,jasonmalinowski/roslyn,aelij/roslyn,tmat/roslyn,gafter/roslyn,gafter/roslyn,agocke/roslyn,mgoertz-msft/roslyn,wvdd007/roslyn,heejaechang/roslyn,tmat/roslyn,shyamnamboodiripad/roslyn,tannergooding/roslyn,physhi/roslyn,mgoertz-msft/roslyn,dotnet/roslyn,KirillOsenkov/roslyn,bartdesmet/roslyn,stephentoub/roslyn,KevinRansom/roslyn,heejaechang/roslyn,sharwell/roslyn,brettfo/roslyn,agocke/roslyn,CyrusNajmabadi/roslyn,stephentoub/roslyn,mavasani/roslyn,AlekseyTs/roslyn,stephentoub/roslyn,bartdesmet/roslyn,bartdesmet/roslyn,panopticoncentral/roslyn,jasonmalinowski/roslyn,ErikSchierboom/roslyn,mavasani/roslyn,jasonmalinowski/roslyn,wvdd007/roslyn,abock/roslyn,AmadeusW/roslyn,reaction1989/roslyn,agocke/roslyn,diryboy/roslyn,ErikSchierboom/roslyn,sharwell/roslyn,tannergooding/roslyn,jmarolf/roslyn,davkean/roslyn,KevinRansom/roslyn,tannergooding/roslyn,mavasani/roslyn,dotnet/roslyn,ErikSchierboom/roslyn,AlekseyTs/roslyn,diryboy/roslyn,KirillOsenkov/roslyn,AmadeusW/roslyn,jmarolf/roslyn,CyrusNajmabadi/roslyn,wvdd007/roslyn