Add missing custom attribute marking to ILTrim TokenBased nodes

[Copilot]

Description

Several TokenBasedNode subclasses in ILTrim were not calling CustomAttributeNode.AddDependenciesDueToCustomAttributes, causing custom attributes on those metadata tables to be silently dropped during trimming.

Nodes fixed

• ParameterNode — was returning null from GetStaticDependencies; now marks parameter custom attributes
• GenericParameterNode — converted from yield return to lazily-initialized DependencyList to integrate CA marking without unnecessary allocations
• GenericParameterConstraintNode — same pattern
• ManifestResourceNode — refactored to have a single AddDependenciesDueToCustomAttributes call and single return at the end; removed early return null in the IgnoreDescriptors path so CA marking is never bypassed

Intentionally skipped (problematic)

InterfaceImpl, StandAloneSig, TypeSpec — along with the already-excluded MethodSpec, TypeRef, AssemblyRef, MemberRef, ModuleRef.

Test impact

• 20 previously-failing tests now pass (removed from ILTrimExpectedFailures.txt)
• 5 new expected failures added — OnlyKeepUsed tests that assert unused attribute removal, which requires --used-attrs-only (not yet implemented in ILTrim)
• Fixed spurious diffs in ILTrimExpectedFailures.txt by preserving original line ordering (undoing unintended sort)

Example of the change pattern applied to each node:

// Before (ParameterNode)
public override IEnumerable<DependencyListEntry> GetStaticDependencies(NodeFactory context) => null;

// After
public override IEnumerable<DependencyListEntry> GetStaticDependencies(NodeFactory context)
{
    DependencyList dependencies = null;
    Parameter parameter = _module.MetadataReader.GetParameter(Handle);
    CustomAttributeNode.AddDependenciesDueToCustomAttributes(ref dependencies, context, _module, parameter.GetCustomAttributes());
    return dependencies;
}

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[Copilot]

Pull request overview

This PR fixes ILTrim TokenBasedNode subclasses that weren’t marking dependencies from metadata custom attributes, which caused those attributes (and their referenced constructors/types) to be silently dropped during trimming.

Changes:

• Added CustomAttributeNode.AddDependenciesDueToCustomAttributes marking to additional token-based metadata nodes (Parameter, GenericParameter, GenericParameterConstraint, ManifestResource).
• Refactored affected nodes to return a single dependency list while integrating custom attribute marking.
• Updated ILTrimExpectedFailures.txt to reflect newly passing tests and to add new expected failures for OnlyKeepUsed scenarios that require --used-attrs-only.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/coreclr/tools/ILTrim.Tests/ILTrimExpectedFailures.txt	Updates expected-failure baselines to reflect the new custom-attribute marking behavior.
src/coreclr/tools/ILTrim.Core/DependencyAnalysis/TokenBased/ParameterNode.cs	Marks dependencies introduced by parameter custom attributes.
src/coreclr/tools/ILTrim.Core/DependencyAnalysis/TokenBased/ManifestResourceNode.cs	Consolidates dependency collection and adds manifest resource custom-attribute dependency marking.
src/coreclr/tools/ILTrim.Core/DependencyAnalysis/TokenBased/GenericParameterNode.cs	Switches from yield to an explicit dependency list to integrate generic-parameter custom-attribute marking.
src/coreclr/tools/ILTrim.Core/DependencyAnalysis/TokenBased/GenericParameterConstraintNode.cs	Switches from yield to an explicit dependency list to integrate constraint custom-attribute marking.

[MichalStrehovsky]

@copilot apply the code review feedback

[Copilot]

@copilot apply the code review feedback

Applied both code review items in eb50492:

1. GenericParameterNode — DependencyList is now lazily initialized (null + ??= on first constraint) to avoid unnecessary allocations.
2. ManifestResourceNode — Removed the early return null when IgnoreDescriptors is set. Now wraps the descriptor processing in if (!factory.Settings.IgnoreDescriptors) instead, so the AddDependenciesDueToCustomAttributes call at the end always runs.