ghc: 7.8.3

Starts the process of closing [31609](https://github.com/Homebrew/homebrew/issues/31609). The patches previous in :DATA have been merged with this release and consequently are no longer required. There is also currently no dev build available, so that has been scrapped as well.
Indent is off here; everything should use two-space indents, so there shouldn't need to be a 1-space indent in the middle like this.