This patch is a big refactoring of llvm-diff. It doesn't add new features, but it re-organizes the old features, so I can insert the MetadataEngine to use the same infrastructure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127627 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed