Refactor for clarity and efficiency.

The PPC GetSymbolFromOperand already prefixed stubs of MO_ExternalSymbol, so
this should be a nop.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196059 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead declarations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196063 91177308-0d34-0410-b5e6-96231b3b80d8
Rename test with misspelt filename

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196064 91177308-0d34-0410-b5e6-96231b3b80d8
Change the default of AsmWriterClassName and isMCAsmWriter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196065 91177308-0d34-0410-b5e6-96231b3b80d8
Remove dead code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196066 91177308-0d34-0410-b5e6-96231b3b80d8
Remove #if 0 declarations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196067 91177308-0d34-0410-b5e6-96231b3b80d8