[GHC] #9247: Document -XDatatypeContexts in flag reference

[GHC]

#9247: Document -XDatatypeContexts in flag reference
-------------------------------------+-------------------------------------
              Reporter:  goldfire    |            Owner:  goldfire
                  Type:  bug         |           Status:  new
              Priority:  low         |        Milestone:  7.10.1
             Component:              |          Version:  7.9
  Documentation                      |         Keywords:
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:
       Type of failure:              |  Related Tickets:  #1880
  None/Unknown                       |
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------
Changes (by thomie):

 * version:  7.8.2 => 7.9
 * related:   => #1880
 * milestone:   => 7.10.1


--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9247#comment:1>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler