[llvm] [GlobalISel] Use G_ANYEXT instead of G_ZEXT for shift amount widening (PR #223136)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,34 @@
+; RUN: llc -mtriple=aarch64 -global-isel -verify-machineinstrs %s -o - | FileCheck %s
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arsenm wrote:

```suggestion
; RUN: llc -global-isel -mtriple=aarch64 < %s | FileCheck %s
```

https://github.com/llvm/llvm-project/pull/223136