Make findIndices fuse
Make findIndices fuse

Summary:
Steal the findIndices implementation from Data.Sequence, that can
participate in fold/build fusion

Reviewers: nomeata, austin

Reviewed By: nomeata, austin

Subscribers: thomie, carter, ezyang, simonmar

Differential Revision: https://phabricator.haskell.org/D345

tjakway/ghcjvm,mcschroeder/ghc,ml9951/ghc,christiaanb/ghc,ghc-android/ghc,ezyang/ghc,forked-upstream-packages-for-ghcjs/ghc,mcschroeder/ghc,forked-upstream-packages-for-ghcjs/ghc,TomMD/ghc,vTurbine/ghc,AlexanderPankiv/ghc,wxwxwwxxx/ghc,nkaretnikov/ghc,gridaphobe/ghc,siddhanathan/ghc,mettekou/ghc,vTurbine/ghc,mcschroeder/ghc,snoyberg/ghc,snoyberg/ghc,elieux/ghc,AlexanderPankiv/ghc,ghc-android/ghc,TomMD/ghc,ezyang/ghc,forked-upstream-packages-for-ghcjs/ghc,acowley/ghc,vTurbine/ghc,jstolarek/ghc,green-haskell/ghc,siddhanathan/ghc,anton-dessiatov/ghc,AlexanderPankiv/ghc,TomMD/ghc,mfine/ghc,sgillespie/ghc,tjakway/ghcjvm,sdiehl/ghc,tjakway/ghcjvm,olsner/ghc,nushio3/ghc,nushio3/ghc,mettekou/ghc,ghc-android/ghc,ezyang/ghc,da-x/ghc,christiaanb/ghc,nathyong/microghc-ghc,gcampax/ghc,TomMD/ghc,nathyong/microghc-ghc,fmthoma/ghc,snoyberg/ghc,tjakway/ghcjvm,forked-upstream-packages-for-ghcjs/ghc,nkaretnikov/ghc,vTurbine/ghc,mettekou/ghc,AlexanderPankiv/ghc,forked-upstream-packages-for-ghcjs/ghc,nushio3/ghc,wxwxwwxxx/ghc,green-haskell/ghc,ezyang/ghc,nathyong/microghc-ghc,mfine/ghc,ezyang/ghc,snoyberg/ghc,nkaretnikov/ghc,wxwxwwxxx/ghc,mettekou/ghc,shlevy/ghc,urbanslug/ghc,shlevy/ghc,sdiehl/ghc,tjakway/ghcjvm,acowley/ghc,wxwxwwxxx/ghc,mcschroeder/ghc,green-haskell/ghc,christiaanb/ghc,GaloisInc/halvm-ghc,nathyong/microghc-ghc,forked-upstream-packages-for-ghcjs/ghc,gcampax/ghc,vikraman/ghc,nathyong/microghc-ghc,anton-dessiatov/ghc,mcschroeder/ghc,urbanslug/ghc,bitemyapp/ghc,elieux/ghc,ml9951/ghc,gridaphobe/ghc,ml9951/ghc,nathyong/microghc-ghc,anton-dessiatov/ghc,bitemyapp/ghc,sgillespie/ghc,gridaphobe/ghc,urbanslug/ghc,jstolarek/ghc,olsner/ghc,christiaanb/ghc,jstolarek/ghc,bitemyapp/ghc,fmthoma/ghc,siddhanathan/ghc,vikraman/ghc,anton-dessiatov/ghc,urbanslug/ghc,ezyang/ghc,da-x/ghc,acowley/ghc,nushio3/ghc,GaloisInc/halvm-ghc,mcschroeder/ghc,ghc-android/ghc,fmthoma/ghc,sdiehl/ghc,ghc-android/ghc,da-x/ghc,snoyberg/ghc,fmthoma/ghc,wxwxwwxxx/ghc,ghc-android/ghc,ml9951/ghc,jstolarek/ghc,olsner/ghc,mcschroeder/ghc,gridaphobe/ghc,GaloisInc/halvm-ghc,da-x/ghc,sgillespie/ghc,AlexanderPankiv/ghc,urbanslug/ghc,oldmanmike/ghc,vikraman/ghc,siddhanathan/ghc,snoyberg/ghc,bitemyapp/ghc,olsner/ghc,sgillespie/ghc,mettekou/ghc,sdiehl/ghc,elieux/ghc,siddhanathan/ghc,mfine/ghc,urbanslug/ghc,AlexanderPankiv/ghc,nushio3/ghc,jstolarek/ghc,nushio3/ghc,acowley/ghc,TomMD/ghc,gcampax/ghc,sgillespie/ghc,elieux/ghc,shlevy/ghc,tjakway/ghcjvm,GaloisInc/halvm-ghc,vTurbine/ghc,mfine/ghc,ghc-android/ghc,fmthoma/ghc,green-haskell/ghc,christiaanb/ghc,mfine/ghc,oldmanmike/ghc,olsner/ghc,da-x/ghc,vikraman/ghc,anton-dessiatov/ghc,snoyberg/ghc,shlevy/ghc,forked-upstream-packages-for-ghcjs/ghc,wxwxwwxxx/ghc,TomMD/ghc,tjakway/ghcjvm,nkaretnikov/ghc,sdiehl/ghc,sgillespie/ghc,da-x/ghc,nkaretnikov/ghc,fmthoma/ghc,sgillespie/ghc,nkaretnikov/ghc,olsner/ghc,urbanslug/ghc,christiaanb/ghc,mettekou/ghc,ml9951/ghc,da-x/ghc,gcampax/ghc,nathyong/microghc-ghc,oldmanmike/ghc,anton-dessiatov/ghc,acowley/ghc,shlevy/ghc,anton-dessiatov/ghc,fmthoma/ghc,AlexanderPankiv/ghc,oldmanmike/ghc,nushio3/ghc,acowley/ghc,acowley/ghc,oldmanmike/ghc,mfine/ghc,siddhanathan/ghc,ml9951/ghc,green-haskell/ghc,gcampax/ghc,GaloisInc/halvm-ghc,mettekou/ghc,GaloisInc/halvm-ghc,oldmanmike/ghc,vikraman/ghc,nkaretnikov/ghc,oldmanmike/ghc,wxwxwwxxx/ghc,gcampax/ghc,vTurbine/ghc,vikraman/ghc,sdiehl/ghc,mfine/ghc,gridaphobe/ghc,gridaphobe/ghc,bitemyapp/ghc,olsner/ghc,gridaphobe/ghc,gcampax/ghc,elieux/ghc,elieux/ghc,shlevy/ghc,vikraman/ghc,elieux/ghc,sdiehl/ghc,vTurbine/ghc,ml9951/ghc,christiaanb/ghc,ezyang/ghc,siddhanathan/ghc,ml9951/ghc,TomMD/ghc,GaloisInc/halvm-ghc,shlevy/ghc