Make RedirectedFileSystem::openFilForRead(path)->status() the same as
RedirectedFileSystem::status(path). Previously we would just get the
status of the underlying real file, which would not have the IsVFSMapped
bit set.
This fixes rebuilding a module that has an include that is relative to
the includer where we will lookup the real path of that file before we
lookup the VFS location.
rdar://problem/23640339
llvm-svn: 255312