ghc-options parsing of quoted strings is slightly non-obvious

Say, for instance, that I would like to pass `-with-rtsopts="-I0 -qg"` to `ghc`. I might try adding the following to my cabal file,
```
ghc-options: -with-rtsopts="-I0 -qg"
```
However, this would result in Cabal passing `'-with-rtsopts="-I0' '-qg"'` to `ghc` instead, resulting in a rather confusing error.

To accomplish my goal it seems I instead need to quote the entire argument,
```
ghc-options: "-with-rtsopts=-I0 -qg"
```

While I can see the rationale here, it is a bit surprising and the errors that are produced when one gets it wrong aren't so great. Is there any reason not to allow quoting anywhere in `ghc-options`?