[llvm] [Matrix] Add tests identifying GVN and DSE opportunities for matrix store / load intrinsics (PR #163573)

[Florian Hahn via llvm-commits]

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@@ -0,0 +1,45 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -passes=gvn -S < %s | FileCheck %s
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fhahn wrote:

```suggestion
; RUN: opt -passes=gvn -S %s | FileCheck %s
```

https://github.com/llvm/llvm-project/pull/163573