[project @ 2001-11-09 16:41:15 by simonpj] --------------------------------------- 	Fix an obscure overlapping-instance bug 	---------------------------------------
[project @ 2001-11-09 16:41:15 by simonpj]
---------------------------------------
	Fix an obscure overlapping-instance bug
	---------------------------------------

	MERGE TO STABLE BRANCH

When searching for instances, we used bale out if the type
we seek could be instantiated to match the instance (because
it might be so instantiated later, in which case we don't
want to miss the opportunity).

The bug was that we used *matching* whereas we should use
*unification*.

Comments in the file InstEnv.

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