[llvm] [ConstantFolding] Add ilogb in isMathLibCallNoop (PR #122582)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,13 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -O1 -S | FileCheck %s
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arsenm wrote:

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

Pass tests should run the minimum set of required passes 

https://github.com/llvm/llvm-project/pull/122582