Recognize mftbl as alias for mftb, for symmetry with mttb.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214769 91177308-0d34-0410-b5e6-96231b3b80d8
Document the "emission kind" field of the DICompileUnit in LLVM's Source Level Debugging metadata.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214771 91177308-0d34-0410-b5e6-96231b3b80d8
Correct the emission kind constants committed in r214771

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214772 91177308-0d34-0410-b5e6-96231b3b80d8