[llvm] [AMDGPU] Gate runtime unroll of LDS loops instead of overriding it (PR #222853)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,415 @@
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -mcpu=gfx950 -passes=loop-unroll \
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arsenm wrote:

```suggestion
; RUN: opt -mtriple=amdgpu9.50-amd-amdhsa -passes=loop-unroll \
```

https://github.com/llvm/llvm-project/pull/222853