Support for JavaScript === and !== operators.

Reviewers: klimek, djasper

Reviewed By: klimek

CC: cfe-commits, klimek

Differential Revision: http://llvm-reviews.chandlerc.com/D2231

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195251 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify fix proposed in r195240.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@195253 91177308-0d34-0410-b5e6-96231b3b80d8