Features: Don't test cxx_contextual_conversions with MSVC.

VS2013 and above to conform to the updated cxx_contextual_conversions proposal,
but VS2010 and above pass the test. I am hesitant to say that VS2010 and above
meet all the requirements of the proposal currently.
Features: Teach windows msvc which are the default compiler versions.
Features: test features actually supported by MSVC min supported.
Features: Teach windows msvc which are the default compiler versions.
Compile Features: Can't use final as only MSVC 2015 and above support it.
Feature: Correct initializer lists to be supported in 2015 and above.

Previous Visual Studio releases said they supported initializer lists but
silently produced bad code.
Features: Don't test cxx_decltype_incomplete_return_types with MSVC.

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.
Merge topic 'feature_record_msvc' into next

edcf86ec Features: Don't test cxx_decltype_incomplete_return_types with MSVC.
a114dfa0 Feature: Correct initializer lists to be supported in 2015 and above.
1a6b7625 Compile Features: Can't use final as only MSVC 2015 and above support it.
f79180f5 Features: Teach windows msvc which are the default compiler versions.
6c8e8e6d Features: test features actually supported by MSVC min supported.
85c49404 Features: Teach windows msvc which are the default compiler versions.
9dfde24f Features: Don't test cxx_contextual_conversions with MSVC.