[GHC] #10752: Print which warning-flag controls/enabled an emitted warning

[GHC]

#10752: Print which warning-flag controls/enabled an emitted warning
-------------------------------------+-------------------------------------
        Reporter:  hvr               |                Owner:  barrucadu
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:  8.2.1
       Component:  Compiler          |              Version:
      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 Rev(s):  Phab:D1943
       Wiki Page:  Design/Warnings   |
-------------------------------------+-------------------------------------
Changes (by barrucadu):

 * differential:  Phab:D1934 => Phab:D1943


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10752#comment:14>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler