This reverts commit r206934 and r206935.

The original messages were:
  "Driver: Honor %INCLUDE% when built with MinGW"
  "Add missing test triples"

The test was still failing on OS X.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@206973 91177308-0d34-0410-b5e6-96231b3b80d8