[llvm] s390x: pattern match saturated truncation (PR #155377)

[Folkert de Vries via llvm-commits]

================
@@ -1,3 +1,4 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
----------------
folkertdev wrote:

I reran the script here, because this test actually does fail locally (but it already did, or at least the error does not seem related to the changes here). I removed it.

https://github.com/llvm/llvm-project/pull/155377