[llvm] [MIR2Vec] Fixing non x86 unittest failures (PR #162381)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

LGTM.

Might not be a bad idea to add a reason for the skip though?

```c++
  GTEST_SKIP() << "Skipping single test";
```

https://github.com/llvm/llvm-project/pull/162381