Robert Maynard authored Jan 06, 2015 and Brad King committed Jan 11, 2015

Notes:
VS2015 and above are the only MSVC versions to support cxx_final, so remove
usages from the tests, and instead only test for cxx_override.

VS2012 and above to conform to cxx_decltype_incomplete_return_types
proposal, but without support for auto return types the dcl.type.simple
example in the proposal doesn't compile.

VS2013 and above to conform to the updated cxx_contextual_conversions proposal,
but VS2010 and above pass the test.

Compilers such as MSVC have no explicit flags to enable C++11 mode,
it just is always on. So only run the link tests with compilers that require
a flag to specify the language version.