[llvm] [Attributor] Do not delete side-effect-free callbr (PR #205052)

[Nikita Popov via llvm-commits]

================
@@ -0,0 +1,21 @@
+; RUN: opt -passes=attributor -verify-each -S < %s | FileCheck %s
----------------
nikic wrote:

```suggestion
; RUN: opt -passes=attributor -S < %s | FileCheck %s
```
And use UTC.

https://github.com/llvm/llvm-project/pull/205052