[PATCH] [-fms-extensions] Add support for __FUNCDNAME__

[Sean Silva]

  FWIW, it might not be as rare as you think. These sorts of macros end up being used in all manner of assertion, tracing, and debug macros which are often heavily used themselves. For example, I've seen codebases with a tracer macro on entry to a significant proportion (>20%) of the functions.

http://llvm-reviews.chandlerc.com/D2109