[llvm] [polly] [SimpleLoopUnswitch] Reland "Generalize the notion of trivial unswitching" (PR #204934)

[Nikita Popov via llvm-commits]

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@@ -0,0 +1,52 @@
+; RUN: opt < %s -passes='loop-mssa(loop-rotate,simple-loop-unswitch<nontrivial;trivial>)' -verify-memoryssa -disable-output
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nikic wrote:

```suggestion
; RUN: opt < %s -passes='loop-mssa(loop-rotate,simple-loop-unswitch)' -verify-memoryssa -disable-output
```
Confusing pass parameters. I think it's equivalent to this?

Also, is it possible to directly use the result of loop-rotate as input, or does that make the issue not reproduce?

https://github.com/llvm/llvm-project/pull/204934