`foo'` links to foo

[Ziyang Liu]

While 'foo'' and `foo'' both correctly link to foo', `foo'` links to foo, which seems like a bug.

[Hécate]

Alright, I can reproduce it with the following code:

module Module where

-- | This is the `foo'` function.
foo' :: ()
foo' = ()

❯ haddock Module.hs 
Haddock coverage:
Warning: Package name is not available.
Warning: 'foo' is out of scope.
    If you qualify the identifier, haddock can try to link it anyway.
  50% (  1 /  2) in 'Module'
  Missing documentation for:
    Module header

[Hécate]

closed by #1483