Well, the patch was rejected, more or less because people felt it overlapped with pgfincore too much. I don't particularly agree, because pgfincore can't load data into shared buffers and doesn't work on Windows, but other people felt differently. There was talk of polishing up pgfincore for possible inclusion in contrib, perhaps adding this functionality along the way, but AFAIK there's been no activity on that.
It wasn't rejected, it was returned with feedback with generally positive reviews. I think the main feedback was that it should provide a single-argument overloaded function that takes just the object name and applies reasonable defaults for the remaining arguments, for example 'main', 'buffer',NULL,NULL. I had thought that the worry about overlap with pgfincore was mostly resolved favorably, but perhaps I misread the situation.
I'd like to see it revived for 9.4 if you are willing.