[clang] [clang-tools-extra] [llvm] [clang] Introduce diagnostics suppression mappings (PR #112517)

[kadir çetinkaya via llvm-commits]

================
@@ -108,6 +108,9 @@ class DiagnosticOptions : public RefCountedBase<DiagnosticOptions>{
   /// The file to serialize diagnostics to (non-appending).
   std::string DiagnosticSerializationFile;
 
+  /// File that defines suppression mappings.
----------------
kadircet wrote:

I was dropping that mostly because this is in `DiagnosticOptions`, but adding those to names to be consistent with others here.

https://github.com/llvm/llvm-project/pull/112517