[VFS] Implement `RedirectingFileSystem::getRealPath`.
It fixes the case when Objective-C framework is added as a subframework
through a symlink. When parent framework infers a module map and fails
to detect a symlink, it would add a subframework as a submodule. And
when we parse module map for the subframework, we would encounter an
error like
> error: umbrella for module 'WithSubframework.Foo' already covers this directory
By implementing `getRealPath` "an egregious but useful hack" in
`ModuleMap::inferFrameworkModule` works as expected.
rdar://problem/45821279
Reviewers: bruno, benlangmuir, erik.pilkington
Reviewed By: bruno
Subscribers: hiraditya, dexonsmith, JDevlieghere, cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D54245
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347009 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed
