[GHC] #8190: mention --show-options in --help

[GHC]

#8190: mention --show-options in --help
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        Reporter:  carter            |            Owner:  thoughtpolice
            Type:  feature request   |           Status:  new
        Priority:  highest           |        Milestone:  7.8.1
       Component:  Compiler          |          Version:  7.7
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:  #7843
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Comment (by jstolarek):

 I have no strong reasons to object. I'm just not sure if this is the most
 important info that should be mentioned by `--help`, but I guess it won't
 do any harm.

 Replying to [comment:5 carter]:
 > listing all of the documented options
 Just to be clear - `--show-options` lists all options, whether documented
 or not :) Do we have any options that we would like to keep hidden from
 users?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8190#comment:6>
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