[WIP] Fix test failure in jitstress2 JIT assert during DependencyInjection.Tests

[Copilot]

• Inspect CI context and issue details
• Read applicable repository/JIT/native/build instructions
• Identify likely async-transform profile flag propagation gap
• Complete required CoreCLR baseline build before editing
• Apply the minimal JIT fix
• Add or run focused regression coverage for the failing DependencyInjection jitstress case
• Run targeted build/test/format validation
• Run secret scan and parallel validation

• Fixes [ci-scan] Test failure: jitstress2 JIT assert 'Missing BBF_PROF_WEIGHT flag' in fgprofile.cpp crashes DependencyInjection.Tests #134304
• Fixes [ci-scan] JIT assert: Missing BBF_PROF_WEIGHT flag in fgprofile.cpp during Transform async (jitstress1) #134295

[azure-pipelines]

Azure Pipelines:
16 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/runtime-infrastructure
See info in area-owners.md if you want to be subscribed.

[dotnet-policy-service]

Tagging subscribers to this area: @JulieLeeMSFT, @jakobbotsch
See info in area-owners.md if you want to be subscribed.

[AndyAyersMS]

@copilot see if this also fixes #134295

[Copilot]

@copilot see if this also fixes #134295

I checked #134295. It has the same assertion/source location and the same async-transform phase, and one of its failures is the same ServiceProviderEngineScope.DisposeAsync method, so this PR’s shared async OSR profile-flag fix should cover it as the same root cause.

I also attempted local DOTNET_JitStress=1 library smoke runs for DependencyInjection and System.Private.Xml, but this checkout’s current shared-framework/targeting-pack layout failed before test execution, so I don’t have a completed local jitstress1 library pass to cite.

[AndyAyersMS]

@jakobbotsch ptal

[azure-pipelines]

Azure Pipelines:
Successfully started running 5 pipeline(s).
11 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[Copilot]

Copilot review overview

🔵 Needs a closer look

The JIT transformation change warrants final human review before approval.

Review effort: Lite
Findings: None

What changed in this PR

Fixes a CoreCLR JIT profile-flag assertion during async transformation and adds targeted jitstress2 regression coverage.

Changes:

• Propagates BBF_PROF_WEIGHT to synthesized OSR jump blocks.
• Adds async regression coverage.
• Configures isolated tiered-PGO jitstress execution.

File	Description
src/​tests/​async/​regression/​134304.csproj	Configures isolated jitstress2 execution.
src/​tests/​async/​regression/​134304.cs	Adds async regression coverage.
src/​coreclr/​jit/​async.cpp	Propagates profile-weight metadata to generated OSR blocks.

[jakobbotsch]

Didn't notice this. I submitted the same change with a bit more clean up in #134325. I don't think we need the test given that this is already caught in CI.. I'll close this one.