Fix #3170: Allow coalescing of the same node during register allocation.   The x86 code generator sometimes generates nop moves like   movl %vI_a %vI_a, but we'll just ignore them for coalescing   purposes instead of emitting an error. It shouldn't hurt anything.
Fix #3170: Allow coalescing of the same node during register allocation.
  The x86 code generator sometimes generates nop moves like
  movl %vI_a %vI_a, but we'll just ignore them for coalescing
  purposes instead of emitting an error. It shouldn't hurt anything.

tjakway/ghcjvm,acowley/ghc,mcschroeder/ghc,nushio3/ghc,shlevy/ghc,gcampax/ghc,oldmanmike/ghc,anton-dessiatov/ghc,spacekitteh/smcghc,AlexanderPankiv/ghc,TomMD/ghc,ryantm/ghc,vikraman/ghc,elieux/ghc,ezyang/ghc,tibbe/ghc,GaloisInc/halvm-ghc,snoyberg/ghc,lukexi/ghc-7.8-arm64,fmthoma/ghc,forked-upstream-packages-for-ghcjs/ghc,forked-upstream-packages-for-ghcjs/ghc,lukexi/ghc-7.8-arm64,forked-upstream-packages-for-ghcjs/ghc,siddhanathan/ghc,acowley/ghc,jstolarek/ghc,christiaanb/ghc,lukexi/ghc,elieux/ghc,vTurbine/ghc,mcmaniac/ghc,bitemyapp/ghc,mcschroeder/ghc,gcampax/ghc,ilyasergey/GHC-XAppFix,tjakway/ghcjvm,anton-dessiatov/ghc,ghc-android/ghc,fmthoma/ghc,ekmett/ghc,ezyang/ghc,sdiehl/ghc,jstolarek/ghc,ezyang/ghc,mfine/ghc,da-x/ghc,siddhanathan/ghc,spacekitteh/smcghc,oldmanmike/ghc,urbanslug/ghc,sgillespie/ghc,ml9951/ghc,anton-dessiatov/ghc,oldmanmike/ghc,nathyong/microghc-ghc,ml9951/ghc,ezyang/ghc,olsner/ghc,mfine/ghc,gridaphobe/ghc,wxwxwwxxx/ghc,sgillespie/ghc,bitemyapp/ghc,oldmanmike/ghc,mfine/ghc,sdiehl/ghc,urbanslug/ghc,gcampax/ghc,sgillespie/ghc,lukexi/ghc-7.8-arm64,ryantm/ghc,shlevy/ghc,ezyang/ghc,gcampax/ghc,gridaphobe/ghc,shlevy/ghc,anton-dessiatov/ghc,olsner/ghc,holzensp/ghc,ekmett/ghc,anton-dessiatov/ghc,frantisekfarka/ghc-dsi,tibbe/ghc,vTurbine/ghc,nathyong/microghc-ghc,tibbe/ghc,olsner/ghc,hferreiro/replay,sdiehl/ghc,tjakway/ghcjvm,mettekou/ghc,mcschroeder/ghc,nomeata/ghc,lukexi/ghc-7.8-arm64,urbanslug/ghc,nomeata/ghc,tibbe/ghc,gridaphobe/ghc,vTurbine/ghc,nomeata/ghc,hferreiro/replay,TomMD/ghc,TomMD/ghc,mettekou/ghc,nushio3/ghc,da-x/ghc,vikraman/ghc,forked-upstream-packages-for-ghcjs/ghc,christiaanb/ghc,bitemyapp/ghc,green-haskell/ghc,christiaanb/ghc,urbanslug/ghc,TomMD/ghc,AlexanderPankiv/ghc,wxwxwwxxx/ghc,oldmanmike/ghc,ilyasergey/GHC-XAppFix,nushio3/ghc,mcschroeder/ghc,gcampax/ghc,mfine/ghc,GaloisInc/halvm-ghc,fmthoma/ghc,ml9951/ghc,mcschroeder/ghc,tibbe/ghc,nathyong/microghc-ghc,wxwxwwxxx/ghc,mcschroeder/ghc,green-haskell/ghc,nomeata/ghc,elieux/ghc,spacekitteh/smcghc,shlevy/ghc,gcampax/ghc,tjakway/ghcjvm,vikraman/ghc,green-haskell/ghc,elieux/ghc,olsner/ghc,frantisekfarka/ghc-dsi,snoyberg/ghc,tjakway/ghcjvm,mcmaniac/ghc,ghc-android/ghc,nkaretnikov/ghc,wxwxwwxxx/ghc,oldmanmike/ghc,snoyberg/ghc,urbanslug/ghc,anton-dessiatov/ghc,wxwxwwxxx/ghc,nushio3/ghc,nathyong/microghc-ghc,wxwxwwxxx/ghc,frantisekfarka/ghc-dsi,forked-upstream-packages-for-ghcjs/ghc,ezyang/ghc,mettekou/ghc,mfine/ghc,mcmaniac/ghc,vTurbine/ghc,jstolarek/ghc,siddhanathan/ghc,fmthoma/ghc,acowley/ghc,ghc-android/ghc,mettekou/ghc,vikraman/ghc,ilyasergey/GHC-XAppFix,ml9951/ghc,gridaphobe/ghc,lukexi/ghc,nathyong/microghc-ghc,lukexi/ghc-7.8-arm64,GaloisInc/halvm-ghc,frantisekfarka/ghc-dsi,lukexi/ghc,mettekou/ghc,fmthoma/ghc,da-x/ghc,tjakway/ghcjvm,da-x/ghc,sdiehl/ghc,gridaphobe/ghc,ml9951/ghc,fmthoma/ghc,siddhanathan/ghc,ryantm/ghc,hferreiro/replay,ghc-android/ghc,mfine/ghc,GaloisInc/halvm-ghc,mcmaniac/ghc,spacekitteh/smcghc,vTurbine/ghc,mettekou/ghc,ryantm/ghc,GaloisInc/halvm-ghc,shlevy/ghc,da-x/ghc,shlevy/ghc,frantisekfarka/ghc-dsi,spacekitteh/smcghc,ml9951/ghc,ekmett/ghc,TomMD/ghc,shlevy/ghc,olsner/ghc,hferreiro/replay,green-haskell/ghc,acowley/ghc,olsner/ghc,jstolarek/ghc,nushio3/ghc,mcmaniac/ghc,christiaanb/ghc,acowley/ghc,christiaanb/ghc,sgillespie/ghc,nathyong/microghc-ghc,hferreiro/replay,GaloisInc/halvm-ghc,hferreiro/replay,GaloisInc/halvm-ghc,ezyang/ghc,sdiehl/ghc,acowley/ghc,ilyasergey/GHC-XAppFix,lukexi/ghc,gridaphobe/ghc,elieux/ghc,vTurbine/ghc,ml9951/ghc,holzensp/ghc,da-x/ghc,ekmett/ghc,holzensp/ghc,ryantm/ghc,AlexanderPankiv/ghc,holzensp/ghc,oldmanmike/ghc,nomeata/ghc,ekmett/ghc,snoyberg/ghc,elieux/ghc,mfine/ghc,nkaretnikov/ghc,ghc-android/ghc,siddhanathan/ghc,TomMD/ghc,bitemyapp/ghc,wxwxwwxxx/ghc,anton-dessiatov/ghc,sgillespie/ghc,forked-upstream-packages-for-ghcjs/ghc,green-haskell/ghc,ghc-android/ghc,vikraman/ghc,sgillespie/ghc,nkaretnikov/ghc,vikraman/ghc,bitemyapp/ghc,AlexanderPankiv/ghc,snoyberg/ghc,snoyberg/ghc,sgillespie/ghc,ml9951/ghc,AlexanderPankiv/ghc,lukexi/ghc,elieux/ghc,ghc-android/ghc,da-x/ghc,urbanslug/ghc,tjakway/ghcjvm,olsner/ghc,nkaretnikov/ghc,forked-upstream-packages-for-ghcjs/ghc,christiaanb/ghc,holzensp/ghc,siddhanathan/ghc,nkaretnikov/ghc,sdiehl/ghc,urbanslug/ghc,mettekou/ghc,vikraman/ghc,acowley/ghc,mcschroeder/ghc,hferreiro/replay,nushio3/ghc,jstolarek/ghc,christiaanb/ghc,fmthoma/ghc,nkaretnikov/ghc,siddhanathan/ghc,gridaphobe/ghc,AlexanderPankiv/ghc,snoyberg/ghc,TomMD/ghc,AlexanderPankiv/ghc,gcampax/ghc,nkaretnikov/ghc,sdiehl/ghc,nushio3/ghc,nathyong/microghc-ghc,vTurbine/ghc