What would be a good way of doing that? Mostly I've just been sharing it on google drive when I find something. Should I fork the mirror from github (https://github.com/postgres/postgres)? Forking the entire codebase just to have a 200 line patch and 2 driving scripts seems excessive, but I guess that that is the git philosophy. Or is there a better way than that?
When forking a repository for development purposes, usually the whole repository is not necessary: push only the master branch that you update from time to time and create separate branches for each development patch. If people would like to have a look at your patch, they would simply need to add a remote link to your fork, fetching only the diffs introduced by your additional branch(es) and then to checkout the branch on which your patch is. This has the advantage to let the user merge himself the code with newer code and not getting failures when applying a patch that will get chunks of code rejected over time.
