Fix GHCi macros not shadowing builtins (#8113)

This restores the original behaviour that was broken accidentally during
the refactoring peformed via 4f764d06f3b9899c09a6a459a22d4be694ee45d9.

This has been broken effectively for all GHC 7.6.x releases.
Fix markup in .cabal and update for 7.6.3.4 release