Summary:
This patch extend getTargetDefines and implement handleTargetFeatures
and hasFeature. and define corresponding marco for those features.
Reviewers: asb, apazos, eli.friedman
Differential Revision: https://reviews.llvm.org/D44727
Patch by Kito Cheng.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@329278 91177308-0d34-0410-b5e6-96231b3b80d8