[llvm-undname] Add support for demangling msvc's noexcept types.

Starting in C++17, MSVC introduced a new mangling for function
parameters that are themselves noexcept functions.  This patch
makes llvm-undname properly demangle them.

Patch by Zachary Henkel
Differential Revision: https://reviews.llvm.org/D55769

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350656 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed