[PATCH] Add support for MSVC's __FUNCSIG__

[David Majnemer]

  LGTM

  Note that there is a bit of divergence here with MSVC, we choose different names for the GlobalVariable holding the string constant.

  I suppose it would be nicer for the names to match and fold but that is a relatively minor thing, nothing to hold up this patch.

http://reviews.llvm.org/D3311

BRANCH
  funcsig

ARCANIST PROJECT
  clang