Graduate the TextDiagnostic interface to its own header and source file,
making it accessible to anyone from the Frontend library. Still a good
bit of cleanup to do here, but its a good milestone. This ensures that
*all* of the functionality needed to implement the DiagnosticConsumer is
exposed via the generic interface in some form. No sneaky re-use of
static functions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142086 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed