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
Note that the import kind is not checked yet; this is effectively our old
behavior for "import swift.print".
Infrastructure: move Module::forAllVisibleModules out-of-line, and add
makeStackLambda to STLExtras for using a non-escaping lambda with
std::function.
Swift SVN r6852
