[GHC] #16206: Run Haddock's test suite in CI

[GHC]

#16206: Run Haddock's test suite in CI
-------------------------------------+-------------------------------------
           Reporter:  sjakobi        |             Owner:  (none)
               Type:  task           |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Test Suite     |           Version:  8.6.3
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
-------------------------------------+-------------------------------------
 Many changes in GHC affect Haddock's output, breaking its test suite.

 Recent examples are
 [https://gitlab.haskell.org/ghc/ghc/commit/53874834b779ad0dfbcde6650069c37926da1b79
 5387483] and
 [https://gitlab.haskell.org/ghc/ghc/commit/7cba71fc25af8287db61f6f6aa80d45ce96404a7
 7cba71f].

 If cases like these were caught during CI, they could be fixed
 immediately, avoiding follow-up cleanup work by the Haddock maintainer.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16206>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler