Remove async method inlining restrictions in crossgen2

[jtschuster]

Remove restrictions that prevented async methods from being inlined during ReadyToRun compilation.

All 69 async tests pass with both crossgen2 and composite R2R.

Output of the src/tests/async/execution-context/execution-context.cs was validated manually to ensure inlining is happening for async calls to methods without awaits. In Test(), these two calls were inlined as expected.

runtime/src/tests/async/execution-context/execution-context.cs

Lines 110 to 121 in b797348

	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	private static async Task ChangeThenThrowInlined()
	{
	s_local.Value = 123;
	throw new Exception();
	}
	[MethodImpl(MethodImplOptions.AggressiveInlining)]
	private static async Task ChangeThenReturnInlined()
	{
	s_local.Value = 123;
	}

Fixes #124665

[jtschuster]

/azp run runtime-coreclr crossgen2

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Copilot]

Pull request overview

Removes restrictions that prevented async methods from being inlined during ReadyToRun (crossgen2) compilation, fixing #124665.

Changes:

• Removed four separate guards that blocked inlining of async methods (thunks, variants, calls) in R2R compilation.

Reviewed changes

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

File	Description
CorInfoImpl.ReadyToRun.cs	Removed exception throw for async method inlining
ReadyToRunCompilationModuleGroupBase.cs	Removed cross-module inlining restriction for async methods
ReadyToRunCodegenCompilation.cs	Removed CanInline restriction for async thunks/calls
InliningInfoNode.cs	Removed skip of async thunks in inlining info emission