Sync ruleutils with postgres

We extend ruleutils a bit for our needs and include it in our source code and we have a different version for each pg major such as `ruleutils_11.c`. Ideally these files need to be synced with postgres ruleutils, there is a comment at the beginning of the file as well:
```
This needs to be closely in sync with the core code.
```

Currently, this is not the case, our version of ruleutils has diverged a lot compared to postgres and it makes it harder to make changes and it is getting harder to sync. We should probably sync it at some point and also we should find a good way of preventing it from diverging a lot.