in the abstraction for lit test suites so that the various other layers
of abstraction pick up the same behavioral fix, and so that we still get
a complete list of dependencies for the 'check-all' target.

This should fix the follow-on issues of the same nature with various
other build targets, including Clang targets. Sorry for the churn, and
again thanks to Matt for testing and breaking this more thoroughly.

llvm-svn: 159593