[llvm] Reapply "[msan] Add avx512-intrinsics.ll and avx512-intrinsics-upgrade.ll test case (#123980)" (PR #124500)

[Vitaly Buka via llvm-commits]

vitalybuka wrote:

> Since these are MSan tests, and we want to know how MSan deals with uninitialized memory, undef seems appropriate?

Undef handling is simpler and have dedicated tests.
Here we'd like to see how msan propagate shadow, parameter is actually better.

https://github.com/llvm/llvm-project/pull/124500