Make InlineAsmIdentifierInfo forward-declarable

This helps localize header inclusion in the frontend.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210417 91177308-0d34-0410-b5e6-96231b3b80d8
Remove redundant typedef from MCAsmParserSemaCallback

The last use has been removed in clang r210418.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210419 91177308-0d34-0410-b5e6-96231b3b80d8