Properly encapsulate additional methods and data from AsmParser.

This finally allows AsmParser to no longer list GenericAsmParser as a friend.
All member vars directly accessed by GenericAsmParser have been properly
encapsulated and exposed through the MCAsmParser interface. This reduces the
coupling between AsmParser and GenericAsmParser.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172490 91177308-0d34-0410-b5e6-96231b3b80d8