inplace: Don't add empty component to LD_LIBRARY_PATH when it is empty
inplace: Don't add empty component to LD_LIBRARY_PATH when it is empty

Summary: Avoids a confusing inconsistency when testing #9386 (about ghci finding .so files in .).

Test Plan: validate

Reviewers: austin

Reviewed By: austin

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D593

GHC Trac Issues: #9386

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