[llvm] [AMDGPU] fix the check of inst-order in a test (PR #90744)

[Jay Foad via llvm-commits]

jayfoad wrote:

> However, it feels like that there is no real good way to reduce merge difficulty in this case?

Can you understand _why_ your downstream changes cause churn in these tests? Maybe there is some underlying problem that could be fixed?

> I should close this PR?

Yes :)

https://github.com/llvm/llvm-project/pull/90744