Added a __has_feature() for 'is_constructible'

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@204153 91177308-0d34-0410-b5e6-96231b3b80d8
clang-format: Detect function-like macros only when upper case is used.

Reviewers: djasper

Reviewed By: djasper

CC: cfe-commits, klimek

Differential Revision: http://llvm-reviews.chandlerc.com/D3110

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@204156 91177308-0d34-0410-b5e6-96231b3b80d8