Disable 'is_constructible' tests on MSVC 2013
Disable 'is_constructible' tests on MSVC 2013

MSVC2013 does not give good results for 'is_constructible' tests,
likely due to incompomplete support for expression-SFINAE on that
compiler.  Disable tests relying on that trait, as-if the platform
did not have a native type_traits header.

che2/bde,bloomberg/bde,bloomberg/bde,che2/bde,che2/bde,che2/bde,bloomberg/bde,bloomberg/bde,bloomberg/bde