[llvm] [X86][AVX512] Add missing mayLoad attribute to AVX512 instructions (PR #162036)

[Craig Topper via llvm-commits]

topperc wrote:

`mayLoad` should be inferred from patterns, so I think the bug report implies there is no isel pattern for VCVTTPD2UDQSZ128rm.

https://github.com/llvm/llvm-project/pull/162036