The VFS YAML files contain empty directory entries to describe that it's
returning from a subdirectory before describing new files in the parent.
In the future, we should properly sort and write YAML files avoiding
such empty dirs and mitigate the extra recurson cost. However, since
this is used by previous existing YAMLs, make the traversal work in
their presence.
rdar://problem/24499339
llvm-svn: 264970
The System/ mock is large and too complex for this test. It can cause
the tests to fail in mysterious ways as it depends on the resource dir
being present, which is not really supported for driver tests (using
%clang instead of %clang_cc1). Copy the tree and trim out all the
%unnecessary fat.
llvm-svn: 263718