[GHC] #10347: Spurious "unused constructor" warning with Coercible

[GHC]

#10347: Spurious "unused constructor" warning with Coercible
-------------------------------------+-------------------------------------
        Reporter:  goldfire          |                   Owner:  goldfire
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:
       Component:  Compiler          |                 Version:  7.11
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  warning at compile-time            |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:
-------------------------------------+-------------------------------------

Comment (by simonpj):

 Meh. Good point.  I think this might signal a re-evaluation of the whole
 `DefUse` thing, which is quite complicated to manage, and isn't paying its
 way.

 For top-level-bound things, something more like `tcg_used_rdrnames` (but
 for `Name`s) might work better.

 Simon

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10347#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler