When passing "UnlockXXXOptions" without the preceding '+', the error message is lovely but not all that helpful:

```
Error: VM option 'UnlockExperimentalVMOptions' is experimental and must be enabled via -XX:+UnlockExperimentalVMOptions.
```

```
Error: VM option 'UnlockDiagnosticVMOptions' is diagnostic and must be enabled via -XX:+UnlockDiagnosticVMOptions.
```

A clearer error message would be nice.