Substitution should just substitute, not optimise
Substitution should just substitute, not optimise

This was causing Trac #4524, by optimising
     (e |> co)  to   e
on the LHS of a rule.  Result, the template variable
'co' wasn't bound any more.

Now that substition doesn't optimise, it seems sensible to call
simpleOptExpr rather than substExpr when substituting in the
RHS of rules.  Not a big deal either way.

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