Implement clang_getDiagnosticCategoryText() to provide a way for a client of libclang to accurately
get the diagnostic category name from a serialized diagnostic when the version of libclang used
to read the diagnostic file is newer than the clang that emitted the diagnostic file.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154567 91177308-0d34-0410-b5e6-96231b3b80d8
9 files changed