Fix 8601 check for RayQuery user type

[brendan-duncan]

Fixes #8601

Compiling to SPIR-V crashes when a user-defined struct or class is named
RayQuery (a reserved intrinsic name), e.g. a ray-tracing abstraction that
declares its own RayQuery type inside a namespace.

HLSL has no rule forbidding this; the local declaration should shadow the
reserved name, and the struct should compile like any other.

Added tools/clang/test/CodeGenSPIRV/type.rayquery.user-defined-shadow.hlsl,
which reproduces the issue and checks that the shadowing struct lowers to a
normal OpTypeStruct and that no OpTypeRayQueryKHR is emitted.

Verified that the intrinsic RayQuery still lowers to OpTypeRayQueryKHR
and that existing rayquery CodeGenSPIRV tests continue to pass.

[azure-pipelines]

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[brendan-duncan]

@microsoft-github-policy-service agree

[llvm-beanz]

Thank you for this contribution!

I'm happy with this PR as-is, but I do (oddly) recommend removing the comments. I realize the comments do explain well the code and why it differs from the code around it, but all the code around it is also a mess of bugs that should change because string-matching type names is bad.

[brendan-duncan]

Agreed with the comment removal. I was debating that myself.

[brendan-duncan]

@llvm-beanz Just checking that I'm not missing something from my side for this PR. Not sure what the pending check is "waiting for status to be reported". I looked around for buttons or TODOs I should be doing.

[brendan-duncan]

@llvm-beanz sorry for the poke--do you think you can run the azp tests command so this PR can move forward, before I forget about it again?

[brendan-duncan]

I just saw that since the change was made I needed to request a re-review, so I did that.

[bob80905]

/azp run

[azure-pipelines]

Azure Pipelines:
Successfully started running 1 pipeline(s).

[Copilot]

Pull request overview

Fixes SPIR-V handling of user-defined types named RayQuery.

Changes:

• Uses semantic RayQuery detection instead of name matching.
• Adds a regression test for struct shadowing.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
AstTypeProbe.cpp	Refines opaque-type detection.
LowerTypeVisitor.cpp	Refines RayQuery lowering.
type.rayquery.user-defined-shadow.hlsl	Adds shadowing coverage.

[brendan-duncan]

@bob80905 I pushed some updates addressing copilot's notes.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

[bob80905]

Cool, didn't know you could do implicit check nots on invocation!