Preserve the V1 async-profiler stitch boundary

[steveisok]

Summary

• Mark AsyncProfilerAsyncStateMachineBox<TStateMachine>.MoveNextAsDispatcher as NoInlining so the V1 stitch boundary remains a physical frame.
• Extend the existing V1 method-name contract test to require MethodImplAttributes.NoInlining for that boundary.
• Include every captured DiagnosticMethodInfo declaring type and method name in physical-stack assertion failures, with explicit unknown markers.

Debugger evidence

A checked CoreCLR debugger probe showed that Debug and Release both:

• allocate AsyncProfilerAsyncStateMachineBox<TStateMachine>;
• arm _isLeaf before resume;
• execute through MoveNextAsDispatcher; and
• resolve that frame through DiagnosticMethodInfo when it is physically present.

The compiler lowering differs as expected: the Debug state machine is a class, while the Release state machine is a struct. This rules out an alternate Debug dispatch path, listener activation, box selection, and frame classification as the intended difference. The missing CI frame therefore exposes an unenforced physical-frame contract.

The CI-specific omission was not reproduced locally, including with Debug libraries, checked CoreCLR, CI build properties, tiering disabled, ReadyToRun disabled, and JIT minopts. Normal PR CI should validate the affected Debug/checked legs.

Validation

• ./build.sh clr.corelib+clr.nativecorelib+libs.pretest -rc checked -lc debug
• V1AsyncDispatchMethod_NameContract_IsStable: 2 passed
• StateMachineAsync_ResumeDispatchStack: 1 passed
• StateMachineAsync_InlineCompletionClimb: 1 passed

Fixes #132025
Fixes #132026

Note

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Pull request overview

This PR reinforces the async-profiler V1 “stitch boundary” contract by ensuring AsyncProfilerAsyncStateMachineBox<TStateMachine>.MoveNextAsDispatcher remains a physical (non-inlined) stack frame, and by tightening tests to validate both the naming and non-inlining requirements while improving failure diagnostics.

Changes:

• Mark AsyncProfilerAsyncStateMachineBox<TStateMachine>.MoveNextAsDispatcher as MethodImplOptions.NoInlining to preserve the physical stitch boundary frame.
• Extend the V1 method-name contract test to also require MethodImplAttributes.NoInlining for V1.MoveNextAsDispatcher.
• Improve test diagnostics by capturing and printing full per-frame DeclaringType::Method information (with explicit <unknown-*> markers) when stack-based assertions fail.

Show a summary per file

File	Description
src/libraries/System.Runtime/tests/System.Threading.Tasks.Tests/System.Runtime.CompilerServices/AsyncProfilerV2Tests.cs	Update resume-dispatch capture plumbing to carry diagnostic frame strings into boundary assertions.
src/libraries/System.Runtime/tests/System.Threading.Tasks.Tests/System.Runtime.CompilerServices/AsyncProfilerV1Tests.cs	Extend V1 boundary tests to pass diagnostic frames through and enforce NoInlining for MoveNextAsDispatcher; improve assertion failure messages.
src/libraries/System.Runtime/tests/System.Threading.Tasks.Tests/System.Runtime.CompilerServices/AsyncProfilerTests.cs	Enhance shared helpers to capture diagnostic frame names and thread them into assertion helpers; expose MethodInfo for contract checks.
src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/AsyncTaskMethodBuilderT.cs	Add MethodImplOptions.NoInlining to MoveNextAsDispatcher to preserve the V1 physical stitch boundary frame.

Review details

• Files reviewed: 4/4 changed files
• Comments generated: 0
• Review effort level: Lite

[steveisok]

/ba-g Helix monitor job failed