[cDAC] Implement GetNativeCodeSequencePointsAndVarInfo for cDAC

[barosiak]

Summary

Implement GetNativeCodeSequencePointsAndVarInfo in the cDAC DacDbiImpl. The interface is changed from output-pointer parameters (NativeVarData*, SequencePoints*) to a callback pattern (FP_NATIVEVARINFO_CALLBACK, FP_SEQUENCEPOINT_CALLBACK), since the managed cDAC cannot use the native forDbi allocator.
Also adds TryGetMethodSignature to IRuntimeTypeSystem to fix GetArgCount and ClrDataFrame methods failing on methods without metadata tokens (e.g. async variants), and removes the unused vlMemory member from ICorDebugInfo::VarLoc (with a JIT/EE version GUID bump).

Changes

• dacdbi.idl / dacdbiinterface.h / dacdbiimpl.h - Add callback typedefs, update method signature
• dacdbiimpl.cpp - Rewrite method to use callbacks, remove GetNativeVarData/GetSequencePoints helpers
• module.cpp - Rewrite LoadNativeInfo with callback struct
• IDacDbiInterface.cs - Add VarLocType, VarLoc, NativeVarInfo, DbiOffsetMapping structs, DbiSourceTypes enum and update method signature
• DacDbiImpl.cs - Implement GetNativeCodeSequencePointsAndVarInfo
• DacDbiImpl.NativeCodeInfo.cs - conversion helpers and DEBUG validation
• RuntimeTypeSystem.md - Document TryGetMethodSignature and AsyncMethodData descriptors
• DacDbiImplTests.cs - unit tests for VarLoc type mapping, field-level conversion, and SourceTypes flag conversion
• IRuntimeTypeSystem.cs / RuntimeTypeSystem_1.cs - Add TryGetMethodSignature
• AsyncMethodData.cs / method.hpp / siginfo.hpp / datadescriptor.inc - Expose Sig and cSig fields from AsyncMethodData
• ClrDataFrame.cs - Extract GetFrameMethodDesc helper, update callers to use TryGetMethodSignature
• TypeNameBuilder.cs / MethodSignatureHelpers.cs - Use TryGetMethodSignature for signature resolution

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[Copilot]

Pull request overview

This PR updates the DAC↔DBI contract for GetNativeCodeSequencePointsAndVarInfo to use a callback-based enumeration model (instead of DBI-allocated output buffers), and wires up the managed cDAC (DacDbiImpl) implementation plus supporting interop structs and unit tests.

Changes:

• Replaces out-pointer buffer parameters with callback delegates for native var info and sequence points (IDL + native headers + native implementation + DBI consumer).
• Adds managed interop representations for native debug-info types and implements the cDAC-side method that enumerates var info and sequence points via callbacks.
• Adds unit tests for var location kind mapping and SourceTypes flag conversion.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
src/native/managed/cdac/tests/UnitTests/DacDbiImplTests.cs	Adds unit tests for VarLoc kind/field mapping and SourceTypes flag conversion.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/IDacDbiInterface.cs	Adds managed interop structs/enums and updates method signature to callback-based pattern.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/DacDbiImpl.NativeCodeInfo.cs	Adds conversion helpers, fixed-arg counting helper, and DEBUG legacy validation.
src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/DacDbiImpl.cs	Implements callback-based GetNativeCodeSequencePointsAndVarInfo using cDAC contracts.
src/coreclr/inc/dacdbi.idl	Updates the COM IDL to define callback typedefs and the new method signature.
src/coreclr/inc/cordebuginfo.h	Documents that specific debug-info types are mirrored in managed code.
src/coreclr/debug/inc/dacdbiinterface.h	Updates the native interface signature and adds callback typedefs.
src/coreclr/debug/di/module.cpp	Updates CordbNativeCode::LoadNativeInfo to collect entries via callbacks and initialize its internal containers.
src/coreclr/debug/daccess/dacdbiimpl.h	Updates the native DAC implementation signature to the new callback-based shape.
src/coreclr/debug/daccess/dacdbiimpl.cpp	Rewrites the DAC implementation to enumerate var info / sequence points and invoke callbacks.

[Copilot]

Pull request overview

Copilot reviewed 22 out of 22 changed files in this pull request and generated 4 comments.

[noahfalk]

I agree with the outstanding comments, but otherwise LGTM

[Copilot]

Copilot's findings

• Files reviewed: 32/32 changed files
• Comments generated: 2

[Copilot]

Copilot's findings

• Files reviewed: 35/35 changed files
• Comments generated: 1

[Copilot]

Copilot's findings

• Files reviewed: 36/36 changed files
• Comments generated: 0 new

[Copilot]

Copilot's findings

• Files reviewed: 36/36 changed files
• Comments generated: 2

[Copilot]

Copilot's findings

• Files reviewed: 36/36 changed files
• Comments generated: 1

[rcj1]

/ba-g unrelated wasm tests