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.
Lines 38-44 need to be de-dented, and the end on line 45 removed.

The ends on line 73 and 72 are for the if on 68 and cd on 47, so it looks like there should be an end after line 73 to close the `def install`.