Replace 'noexcept' with '_NOEXCEPT' in <shared_mutex>. This allows us to build the dylib with MSVC, which doesn't support noexcept (sheesh\!). Thanks to K-ballo for the report.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@216384 91177308-0d34-0410-b5e6-96231b3b80d8
Quick hack to lit.cfg to run tests on Windows
Exclude math definitions provided by MSVC12
Enable MSVC12 features
MSVC has trouble with SFINAE, comment out some __invoke overloads (for now)
Added fallback copy/move tuple constructors when =default is not supported
Use parenthesis to workaround an MSVC issue
Workaround for MSVC ICE