Export more Packages functions
Export more Packages functions

Summary:
This patch exports functions for finding the active package
databases and their locations from the Packages module. This
allows GHC API clients to use other tools, like Cabal, to gather
package information that's not directly available from the
binary package db.

Reviewers: duncan, austin

Reviewed By: austin

Subscribers: thomie, carter

Differential Revision: https://phabricator.haskell.org/D514

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