Arith/lower_split.mlir test not working

When we run

```
bazel test //tests/Dialect/Arith/Transforms/runner:lower_split.mlir.test
```

We will get the following error

```
# .---command stderr------------
# | heir-opt: Unknown command line argument '--arith-quarter-wide-int'. Try: 'heir-opt --help'
# | heir-opt: Did you mean '--arith-to-mod-arith'?
# `-----------------------------
```

As the test is now marked as manual, it is not covered in CI.

Also the line `clang -c quarter_to_llvm.c` should be changed to

```bash
clang libquarter_to_llvm.a %t -o a.out
```

As lit has no access to the source file but only the compiled lib.