[llvm] [DAGCombiner] Preserve debug location of original load in fold (conv (load x)) (PR #160236)

[Matt Arsenault via llvm-commits]

================
@@ -0,0 +1,41 @@
+; RUN: llc -mtriple=amdgcn -mcpu=gfx942  < %s | FileCheck %s
----------------
arsenm wrote:

```suggestion
; RUN: llc -mtriple=amdgcn -mcpu=gfx942 < %s | FileCheck %s
```

Test belongs in test/DebugInfo 

https://github.com/llvm/llvm-project/pull/160236