Refactor SerializeDiagnosticsPrinter to using DiagnosticRenderer.  This gives us comparative diagnostics
to TextDiagnosticPrinter.

This certainly can be cleaned up a bit.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146820 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed