[llvm] LoopVectorize/test: clean up intrinsic.ll, regen using UTC (NFC) (PR #70202)

[Florian Hahn via llvm-commits]

fhahn wrote:

Not sure if it is worth auto-generating the checks here; the file mainly tests that we can widen various intrinsics and auto-generating checks here will mean that the test will need updating any time in the future when anything unrelated to intrinsic handling cause changes, adding additional churn.

It also increases the size of the test quite a bit, so if we go with auto-generating it might make sense to split the file up a bit.

https://github.com/llvm/llvm-project/pull/70202