Matthew Pickering authored Jul 03, 2015 and Ben Gamari committed Jul 03, 2015

Each production produced a singleton list.

Similar treatment is applied to the decl_cls parser.

This changes the type of the parseDeclaration entry point to

`parseDeclaration :: P (LHsDecl RdrName)`

and

`parseTypeSignature :: P (LHsDecl RdrName)`

which is in line with the other parser entry points.

This patch also updates the conflict commentary.  There were 4 reduce/reduce
conflicts introduced by `ffc21506` which
refactored tuple constraints.

Reviewers: austin

Reviewed By: austin

Subscribers: thomie, bgamari

Differential Revision: https://phabricator.haskell.org/D1007