Revert "Recommit r179497 after fixing uninitialized variable." until

I can fix the testcases here:

http://lab.llvm.org:8011/builders/clang-native-arm-cortex-a9/builds/6952

This reverts commit r179512 due to testcases specifying triples
that they didn't actually mean and causing failures on other platforms.

llvm-svn: 179513