[clang] [CIR] max-across-vector (vmaxv_*) intrinsics (PR #194401)

[Andrzej Warzyński via cfe-commits]

banach-space wrote:

> @banach-space fyi test cases are not ordered, if you want i can do that once you confirm the structure of test cases looks good :)

LG, please order them 👍🏻 

https://github.com/llvm/llvm-project/pull/194401