[llvm] [NFC] Partial reduce test to demonstrate regression post commit #cc9c64d (PR #162681)

[David Sherwood via llvm-commits]

david-arm wrote:

> @david-arm in the changed test, the attribute has "cpu" field instead of "target-cpu". I believe latter one should be correct because both are yielding different IR and codegen. I hope its fine if I change it to "target-cpu" to avoid one more PR just for this.

You're right this is broken. Sorry about this - I hadn't realised. I'm creating a simple PR now to fix this as it's also broken in another partial-reduce-*** file as well.

https://github.com/llvm/llvm-project/pull/162681