[llvm] [ARM] Fix printing of 'pop' alias. (PR #67181)

[Anton Kochkov via llvm-commits]

https://github.com/XVilka requested changes to this pull request.

I suppose test also should be updated:
```
Failed Tests (1):
     LLVM :: MC/Disassembler/ARM/basic-arm-instructions.txt
```

https://github.com/llvm/llvm-project/pull/67181