Allow both MSVC and Itanium mangling schemes.

Summary:
LLDB on Windows should now be able to demangle Linux/Android symbols.

Also updated CxaDemangle.cpp to be compatible with MSVC.

Depends on D9949, D9954, D10048.

Reviewers: zturner, emaste, clayborg

Reviewed By: clayborg

Subscribers: tberghammer, lldb-commits

Differential Revision: http://reviews.llvm.org/D10040

llvm-svn: 238460