The identifier parser should _not_ accept qualified reserved ops

[harpocrates]

This is really a GHC bug: https://ghc.haskell.org/trac/ghc/ticket/14109, but it causes Haddock to accept and render some impressive nonsense.

module Temp where

-- | See 'Q.case', 'Q.of', 'Q.--', 'Q.as'
foo :: ()
foo = ()

results in case, of, --, and as attempting to be hyperlinked.

[harpocrates]

Fixed in harpocrates@6922aa9. I'll figure where to slot this in (whether on ghc-8.8, ghc-head) after the dust settles.

[harpocrates]

Fixed in 9fcfa37