Replace UIntPtr with nuint on managed JIT/EE interface

[jkotas]

No description provided.

[Copilot]

Pull Request Overview

This PR replaces UIntPtr with nuint throughout the managed JIT/EE interface in the CoreCLR tooling, modernizing the codebase to use the native integer type alias that was introduced in .NET 5.

Key Changes:

• Updated type mappings in the ThunkGenerator input configuration
• Replaced UIntPtr parameters and return types with nuint in generated and manual interface code
• Simplified initialization expressions by removing explicit UIntPtr constructors

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/coreclr/tools/Common/JitInterface/ThunkGenerator/ThunkInput.txt	Updated type mapping configuration to use nuint instead of UIntPtr
src/coreclr/tools/Common/JitInterface/CorInfoTypes.cs	Changed struct fields from UIntPtr to nuint
src/coreclr/tools/Common/JitInterface/CorInfoImpl_generated.cs	Updated generated method signatures and delegate types to use nuint
src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs	Updated manual method implementations and simplified initialization expressions

[jkotas]

cc @dotnet/jit-contrib

[EgorBo]

Is there a motivation behind this change? Also, why not changing IntPtr to nint then?

[jkotas]

My primary motivation was to fix the managed type mapping for size_t that I have noticed when reviewing earlier PR.

There are always more places where you can replace IntPtr more appropriate type...