[llvm] [CodeGen] Add MO_LaneMask type and a new COPY_LANEMASK instruction (PR #151944)

[Jay Foad via llvm-commits]

================
@@ -0,0 +1,13 @@
+# RUN: not llc -mtriple=amdgcn-amd-amdhsa -run-pass=none -filetype=null %s 2>&1 | FileCheck %s
+
+---
+name: test_missing_rparen
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+
+    ; CHECK: [[@LINE+1]]:47: lanemask should be terminated by ')'. 
----------------
jayfoad wrote:

```suggestion
    ; CHECK: [[@LINE+1]]:47: lanemask should be terminated by ')'.
```
Please check the entire patch for where you've added trailing whitespace. There is a lot. Command like "git diff" helpfully highlights it in red.

https://github.com/llvm/llvm-project/pull/151944