[llvm] Bug fixes for ISelLowering for HVX (PR #164416)

[Alexey Karyakin via llvm-commits]

================
@@ -0,0 +1,89 @@
+;; RUN: llc --mtriple=hexagon -mattr=+hvxv79,+hvx-length128b %s -o - | FileCheck %s
+;; Sanity check for lowering masked scatter without assertion errors.
+
----------------
quic-akaryaki wrote:

It does not look the test case was "designed", but the whole failing .ll file included as is. It's pretty big and it's hard to judge what is broken. Since assertion (which one?) is the only symptom, it's also not reliable reproducer.

https://github.com/llvm/llvm-project/pull/164416