[llvm] [SimplifyCFG] Simplify switch instruction that has duplicate arms (PR #114262)

[Nikita Popov via llvm-commits]

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@@ -0,0 +1,172 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -passes=simplifycfg -S | FileCheck %s -check-prefix=SIMPLIFY-CFG
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nikic wrote:

```suggestion
; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s -check-prefix=SIMPLIFY-CFG
```

https://github.com/llvm/llvm-project/pull/114262