JIT: Unify to instParamLookup and improve GVM test coverage

[hez2010]

Extracted from #123323. This PR is the first step in splitting the shared GVM devirtualization work.

It does two things:

• expands the generic virtual method test coverage so the later enablement PRs have good coverage
• refactors devirtualization a bit to replace multiple ad-hoc flags in CORINFO_DEVIRTUALIZATION_INFO with a single instParamLookup

Contributes to #112596

/cc: @jakobbotsch

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[Copilot]

Pull request overview

Refactors CoreCLR devirtualization metadata to use a unified instParamLookup and expands JIT test coverage for generic virtual method (GVM) scenarios to support follow-on GVM devirtualization work.

Changes:

• Add a new GVM-focused runtime lookup/delegate test to broaden devirtualization coverage.
• Replace CORINFO_DEVIRTUALIZATION_INFO ad-hoc flags with instParamLookup, and update JIT devirtualization logic to consume it.
• Update SuperPMI and the managed JitInterface type definitions/serialization to match the new CORINFO_DEVIRTUALIZATION_INFO shape (plus bump the JIT/EE versioning GUID).

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/tests/JIT/Generics/VirtualMethods/generic_virtual_methods.cs	Adds additional GVM/runtime-lookup-related test coverage.
src/coreclr/vm/jitinterface.cpp	Initializes/produces instParamLookup for devirtualization results (replacing older flags).
src/coreclr/jit/importercalls.cpp	Plumbs instParamLookup through devirtualization + guarded devirtualization candidate tracking and inserts instantiation args when required.
src/coreclr/jit/morph.cpp	Simplifies lookup-tree helpers to take CORINFO_LOOKUP directly.
src/coreclr/jit/compiler.h	Updates declarations for the new lookup-tree helper signatures and GDV candidate plumbing.
src/coreclr/inc/corinfo.h	Updates CORINFO_DEVIRTUALIZATION_INFO to carry instParamLookup instead of legacy flags; documents “no lookup needed” sentinel.
src/coreclr/inc/jiteeversionguid.h	Bumps the JIT/EE version GUID for the interface change.
src/coreclr/tools/Common/JitInterface/CorInfoTypes.cs	Mirrors the CORINFO_DEVIRTUALIZATION_INFO layout change in managed definitions.
src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs	Updates managed resolveVirtualMethod implementation to populate instParamLookup and method-context behavior.
src/coreclr/tools/superpmi/superpmi-shared/agnostic.h	Updates SuperPMI record structs to include instParamLookup.
src/coreclr/tools/superpmi/superpmi-shared/methodcontext.cpp	Records/restores/dumps instParamLookup in SuperPMI method contexts.

[Copilot]

info->instParamLookup.lookupKind.runtimeLookupKind is left uninitialized here (only needsRuntimeLookup is set). Even when needsRuntimeLookup is false, this can leak uninitialized data into diagnostics/SuperPMI recordings and make results non-deterministic. Initialize the whole instParamLookup (e.g., zero it) or explicitly set runtimeLookupKind to a defined value before returning.

Suggested change

	memset(&info->resolvedTokenDevirtualizedUnboxedMethod, 0, sizeof(info->resolvedTokenDevirtualizedUnboxedMethod));
	memset(&info->resolvedTokenDevirtualizedUnboxedMethod, 0, sizeof(info->resolvedTokenDevirtualizedUnboxedMethod));
	memset(&info->instParamLookup, 0, sizeof(info->instParamLookup));

[Copilot]

The local name instParam is reused for two different concepts in the same method (CORINFO_METHOD_HANDLE instParam earlier, then GenTree* instParam here). This shadowing is easy to misread and can lead to mistakes during future edits. Rename one/both (e.g., instParamHnd vs instParamNode) to keep the handle and tree clearly distinct.

Suggested change

	GenTree* instParam = getLookupTree(&dvInfo.instParamLookup, GTF_ICON_METHOD_HDL, compileTimeHandle);
	if (instParam == nullptr)
	{
	// If we're inlining, impLookupToTree can return nullptr after recording a fatal observation.
	JITDUMP("Failed to produce the lookup for devirtualized call, sorry.\n");
	return;
	}
	call->gtArgs.InsertInstParam(this, instParam);
	GenTree* instParamNode = getLookupTree(&dvInfo.instParamLookup, GTF_ICON_METHOD_HDL, compileTimeHandle);
	if (instParamNode == nullptr)
	{
	// If we're inlining, impLookupToTree can return nullptr after recording a fatal observation.
	JITDUMP("Failed to produce the lookup for devirtualized call, sorry.\n");
	return;
	}
	call->gtArgs.InsertInstParam(this, instParamNode);

[hez2010]

Test failure seems unrelated.