[llvm] [FunctionAttrs] Handle alias-preserving intrinsic calls correctly (PR #68453)

[Nikita Popov via llvm-commits]

https://github.com/nikic requested changes to this pull request.

This looks like a reasonable improvement to *precision*, but this is not a bug fix.

An argument that gets returned by a function must not be marked as `nocapture`. The return value counts as a capture. The current attributes on the `llvm.amdgcn.make.buffer.rsrc` intrinsic are incorrect.

https://github.com/llvm/llvm-project/pull/68453