Now GenericAsmParser and AsmParser are no longer friends, GenericAsmParser can
simply use the getParser method from MCAsmParserExtension, working through the
MCAsmParser interface. There's no longer a need to overload that method to
cast it to the concrete AsmParser.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172491 91177308-0d34-0410-b5e6-96231b3b80d8