[PCH] Enhance InputFile to also include whether the file is out-of-date.

Previously we would return null for an out-of-date file. This inhibited ASTReader::ReadSLocEntry
from creating a FileID to recover gracefully in such a case.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176332 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed