[GHC] #9068: Don't uninstall signal handlers if none were installed

[GHC]

#9068: Don't uninstall signal handlers if none were installed
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        Reporter:  tomgr                        |            Owner:
            Type:  bug                          |  simonmar
        Priority:  normal                       |           Status:  merge
       Component:  Runtime System               |        Milestone:  7.8.3
      Resolution:                               |          Version:  7.8.2
Operating System:  Windows                      |         Keywords:
 Type of failure:  Incorrect result at runtime  |     Architecture:
       Test Case:                               |  Unknown/Multiple
        Blocking:                               |       Difficulty:
                                                |  Unknown
                                                |       Blocked By:
                                                |  Related Tickets:
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Changes (by simonmar):

 * status:  new => merge
 * milestone:   => 7.8.3


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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9068#comment:2>
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