[llvm] Fix min_vec_size.ll test for changes in vector-combine (PR #145392)

[Tex Riddell via llvm-commits]

tex3d wrote:

The failures from the `Build and Test Linux` check must be unrelated:
```
Unresolved Tests (3):
  lldb-api :: commands/expression/import-std-module/basic/TestImportStdModule.py
  lldb-api :: commands/expression/import-std-module/conflicts/TestStdModuleWithConflicts.py
  lldb-api :: commands/expression/import-std-module/retry-with-std-module/TestRetryWithStdModule.py
```

https://github.com/llvm/llvm-project/pull/145392