Convert PREPARE_SIMPLE_VIRTUAL_CALLSITE usages to use the UCO pattern

[jkoritzinsky]

Contributes to #123864.

Also remove PREPARE_SIMPLE_VIRTUAL_CALLSITE now that it is unused.

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[Copilot]

Pull request overview

This PR converts the remaining PREPARE_SIMPLE_VIRTUAL_CALLSITE usages in dynamicmethod.cpp to use the more efficient UnmanagedCallersOnly (UCO) pattern, and removes the now-unused PREPARE_SIMPLE_VIRTUAL_CALLSITE macro from callhelpers.h. This is part of the larger effort tracked in issue #123864 to replace MethodDescCallSite/CallDescrWorker infrastructure with UnmanagedCallersOnly reverse P/Invoke calls for better performance when invoking managed code from native code.

Changes:

• Converted 5 call sites in LCGMethodResolver to use UnmanagedCallersOnlyCaller pattern
• Added corresponding [UnmanagedCallersOnly] wrapper methods in RuntimeHandles.cs
• Updated method signatures in metasig.h and corelib.h from instance methods (IM_*) to static methods with pointer parameters (SM_Ptr*)
• Removed the deprecated PREPARE_SIMPLE_VIRTUAL_CALLSITE and PREPARE_SIMPLE_VIRTUAL_CALLSITE_USING_SLOT macros

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/coreclr/vm/metasig.h	Added 3 new method signature definitions for the converted methods: ResolveToken, ResolveSignature, and GetEHInfo
src/coreclr/vm/corelib.h	Updated 4 method definitions from instance methods to static methods with pointer parameters
src/coreclr/vm/callhelpers.h	Removed deprecated PREPARE_SIMPLE_VIRTUAL_CALLSITE macros (56 lines) and fixed trailing whitespace
src/coreclr/vm/dynamicmethod.cpp	Converted 5 call sites (ResolveToken, ResolveSignature x2, GetRawEHInfo, GetEHInfo) to use UnmanagedCallersOnlyCaller with explicit GC protection
src/coreclr/System.Private.CoreLib/src/System/RuntimeHandles.cs	Added 4 new [UnmanagedCallersOnly] wrapper methods with exception out-parameters

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 5 comments.

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.

[jkoritzinsky]

/ba-g wbt failures