getOriginalSourceFileName and getOriginalSourceFile can return a StringRef.
MaybeAddSystemRootToFilename doesn't need to return anything, it modifies
its argument.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@166988 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed