[Wasm RyuJIT] Implement SP/FP delta computation

[adamperlin]

These are currently unused but fairly simple to implement on Wasm to get rid of the NYIs.

[azure-pipelines]

Azure Pipelines:
Successfully started running 6 pipeline(s).
10 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]

Pull request overview

Implements Wasm RyuJIT stack-pointer/frame-pointer delta helpers to replace prior NYI stubs, enabling callers that compute frame-relative offsets (e.g., for unwind/stack layout logic) to function without hitting Wasm-specific NYIs.

Changes:

• Implemented CodeGenInterface::genCallerSPtoInitialSPdelta() for Wasm based on the fixed linear-memory frame size.
• Implemented CodeGenInterface::genCallerSPtoFPdelta() for Wasm using existing delta relationships and added basic sign assertions.
• Removed NYI_WASM(...) stubs for the above helpers and for genSPtoFPdelta() (kept as 0 per Wasm frame model).

Suppressed comments (1)

src/coreclr/jit/codegenwasm.cpp:4495

• Local variable name callerSPToInitialSPDelta is inconsistent with the established callerSPtoInitialSPdelta naming used across other backends. Renaming improves consistency and makes grepping/comparison across targets easier.

    int callerSPToInitialSPDelta = -genTotalFrameSize();
    assert(callerSPToInitialSPDelta <= 0);
    return callerSPToInitialSPDelta;

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[azure-pipelines]

Azure Pipelines:
Successfully started running 6 pipeline(s).
10 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 'arch-wasm': @lewing, @pavelsavara
See info in area-owners.md if you want to be subscribed.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

[AndyAyersMS]

We shouldn't be calling these so does it make sense to implement them?

[adamperlin]

We shouldn't be calling these so does it make sense to implement them?

If we don't think we'll ever need them, can we mark them as unreached?

[AndyAyersMS]

We shouldn't be calling these so does it make sense to implement them?

If we don't think we'll ever need them, can we mark them as unreached?

I think so, yes. Just make sure the compiler is ok with it.