Consolidate some TableGen diagnostic helper functions.

TableGen had diagnostic printers sprinkled about in a few places. Pull them
together into a single location in Error.cpp.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133568 91177308-0d34-0410-b5e6-96231b3b80d8
17 files changed