escape(): don't forget the final '\0'
escape(): don't forget the final '\0'

Hopefully should fix random "bad heap profile" failures in the nightly
builds.

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