Use FileEntryRef for PPCallbacks::HasInclude

This fixes the issue where a filename dependendency was missing if the file that
was referenced with __has_include() was accessed through a symlink in an earlier run,
if the file manager was reused between runs.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@370081 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed