Named chunks in module header

[sgraf812]

Apparently, haddock (or the parser, rather) doesn't allow named chunk references in the module header:

-- |
-- $doc
module Foo where

-- $doc
-- foo

Foo.hs:2:1: error: parse error on input ‘-- $doc’
  |
2 | -- $doc
  | ^^^^^^^

[harpocrates]

As is usually the case here, the problem is in GHC's moduleheader production. We could tweak this to also accept

-- $doc
module Foo where

-- $doc
-- foo

The main concern is that chunk references have to be tokens on their own. All of this will become much simpler once I finish https://phabricator.haskell.org/D5057.

[simonmichael]

I guess named chunks in module header didn't happen yet ?