Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
This depends on c-index-test being available in the path.
This should work for CMake builds where swift is built
in its own build folder. I believe this will also work
for Makefile builds, but the buildbot will verify.
Swift SVN r5562
