[llvm] [msan] Overflow intrinsics. (PR #88210)

[Evgenii Stepanov via llvm-commits]

eugenis wrote:

Fixed the code to be insensitive to argument evaluation order.
Removed custom handling of saturating intrinsics - as it turns out, `maybeHandleSimpleNomemIntrinsic` is already doing a good job.

https://github.com/llvm/llvm-project/pull/88210