[llvm] [LoopVectorize][NFC] Rewrite tests to check output of vplan cost model (PR #113697)

[David Green via llvm-commits]

davemgreen wrote:

Sorry for the suggestion, floats are often difficult. I agree it is useful to see the actual value though, not rounded to an integer. Perhaps just make that test less precise if it is really 3.25 so could round either way depending on the environment.

https://github.com/llvm/llvm-project/pull/113697