
Handles clang::DiagnosticsEngine and clang::DiagnosticIDs. For DiagnosticIDs, this mostly migrates from `new DiagnosticIDs` to convenience method `DiagnosticIDs::create()`. Part of cleanup https://github.com/llvm/llvm-project/issues/151026
Handles clang::DiagnosticsEngine and clang::DiagnosticIDs. For DiagnosticIDs, this mostly migrates from `new DiagnosticIDs` to convenience method `DiagnosticIDs::create()`. Part of cleanup https://github.com/llvm/llvm-project/issues/151026