[llvm] [SelectionDAG] Salvage debuginfo when combining load and sext instrs. (PR #169779)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,55 @@
+# This test checks that after SelectionDAG runs, it preserves the debug info that is lost due to the DAGCombiner combining a load and a sext instruction, where the #dbg_value is pointing to the result of the load.
+
+# RUN: llc -O2 %s -mtriple=x86_64-unkown-linux -start-before=x86-isel -stop-after=x86-isel -o - | FileCheck %s --check-prefix=MIR
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arsenm wrote:

```suggestion
# RUN: llc %s -mtriple=x86_64-unkown-linux -start-before=x86-isel -stop-after=x86-isel -o - | FileCheck %s --check-prefix=MIR
```

https://github.com/llvm/llvm-project/pull/169779