[llvm] [NVPTX] Vectorize loads when lowering of byval calls, misc. cleanup (PR #151070)

[Artem Belevich via llvm-commits]

================
@@ -150,8 +150,8 @@ define dso_local void @caller_St4x3(ptr nocapture noundef readonly byval(%struct
   ; CHECK:       )
----------------
Artem-B wrote:

Perhaps it's good opportunity to convert it to automatic checks, too. We do want to see that the values are passed in correct order and not just in a right kind of register matched by a regex.

https://github.com/llvm/llvm-project/pull/151070