RunClang: Pass CompilerInstance to UpdatePredefines
RunClang: Pass CompilerInstance to UpdatePredefines

Teach UpdatePredefines to ask the CompilerInstance for the predefines.
This will allow it to ask the CompilerInstance for other information
too.

bradking/CastXML,CastXML/CastXML,bradking/CastXML,ellert/CastXML,CastXML/CastXML,thewtex/CastXML,thewtex/CastXML,bradking/CastXML,ellert/CastXML,iMichka/CastXML,ellert/CastXML,thewtex/CastXML,iMichka/CastXML,CastXML/CastXML