The flag `Werror=unrecognised-warning-flags` does not turn unrecognised warnings on fatal errors
By running on GHC 9.2.3
```bash
ghc -Werror -Wunrecognised-warning-flags -Wfoo Main.hs
```
I got a compilation error as expected due to the unrecognised warning `Wfoo`. However, by running
```bash
ghc -Werror=unrecognised-warning-flags -Werror=foo Main.hs
```
I only got a warning instead of a compilation error.
issue