[llvm] [BPF] Use 32-bit move for zero extension when possible (PR #77501)

[Yingchi Long via llvm-commits]

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@@ -0,0 +1,34 @@
+; RUN: llc -march=bpfel -mcpu=v3 --filetype=obj < %s | llvm-objdump -d - \
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inclyc wrote:

why not emit assembly directly? e.g.

```diff
- RUN: llc -march=bpfel -mcpu=v3 --filetype=obj < %s
+ RUN: llc -march=bpfel -mcpu=v3 < %s
```


https://github.com/llvm/llvm-project/pull/77501