Pull request overview

This PR extends the ReadyToRun reflection tooling so that method signatures used by R2RDump can be annotated with prefixes that distinguish async-related variants (and other stub kinds), and ensures PGO keys stay consistent with the displayed signatures.

Changes:

• Extend ReadyToRunMethod and PgoInfoKey to carry and incorporate SignaturePrefixes into their computed signature strings.
• In ReadyToRunReader, decode ReadyToRunMethodSigFlags for instance entrypoints and PGO instrumentation records, build corresponding signature prefixes (currently for AsyncVariant), and thread them into ReadyToRunMethod and PgoInfoKey.
• Add explicit NotImplementedException throws when encountering InstantiatingStub or UnboxingStub method signature flags in instance entrypoints or PGO data.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

        public PgoInfoKey(IAssemblyMetadata componentReader, string owningType, EntityHandle methodHandle, string[] instanceArgs, string[] signaturePrefixes)
        {
            ComponentReader = componentReader;
            EntityHandle owningTypeHandle;
            DisassemblingGenericContext genericContext = new DisassemblingGenericContext(typeParameters: Array.Empty<string>(), methodParameters: instanceArgs);