Adding GetStaticBaseAddress cDAC API

[rcj1]

No description provided.

[Copilot]

Pull Request Overview

This PR adds a new cDAC API called GetStaticBaseAddress which provides access to static field base addresses for types. The implementation extracts GC and non-GC static base pointers from the DynamicStaticsInfo structure associated with method tables.

Key changes:

• Implements the GetStaticBaseAddress method in the cDAC interface to replace the legacy implementation fallback
• Adds new runtime type system methods for accessing GC and non-GC static base pointers
• Introduces DynamicStaticsInfo data structure and associated global constants for static field access

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
SOSDacImpl.cs	Implements GetStaticBaseAddress method with validation, contract calls, and debug verification
DynamicStaticsInfo.cs	New data structure for reading GC and non-GC static pointers with masking
RuntimeTypeSystem_1.cs	Adds GetGCStaticsBasePointer and GetNonGCStaticsBasePointer methods to access static fields
Constants.cs	Adds global constants for StaticsPointerMask and DynamicStaticsInfoSize
DataType.cs	Registers DynamicStaticsInfo as a new data type
IRuntimeTypeSystem.cs	Adds interface definitions for the new static base pointer methods
datadescriptor.inc	Defines CDAC type and global mappings for DynamicStaticsInfo
RuntimeTypeSystem.md	Documents the new API methods and data structures

Comments suppressed due to low confidence (3)

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Contracts/Contracts/RuntimeTypeSystem_1.cs:36

• The field name DynamicStaticsInfoSize suggests it contains a size value, but it's declared as TargetPointer which typically represents an address. Consider renaming to clarify its purpose or change the type to nuint if it represents a size.

        internal TargetPointer DynamicStaticsInfoSize { get; }

docs/design/datacontracts/RuntimeTypeSystem.md:478

• The variable target is used but should be _target to match the class field naming convention used elsewhere in the codebase.

        nuint mask = target.ReadGlobal<nuint>(Constants.Globals.StaticsPointerMask);

docs/design/datacontracts/RuntimeTypeSystem.md:493

• The variable target is used but should be _target to match the class field naming convention used elsewhere in the codebase.

        nuint mask = target.ReadGlobal<nuint>(Constants.Globals.StaticsPointerMask);

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