[GHC] #9271: Avoid unnecessary clock_gettime() syscalls in GC stats.

[GHC]

#9271: Avoid unnecessary clock_gettime() syscalls in GC stats.
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        Reporter:  brbr        |            Owner:  simonmar
            Type:  task        |           Status:  new
        Priority:  normal      |        Milestone:
       Component:  Runtime     |          Version:  7.8.2
  System                       |         Keywords:
      Resolution:              |     Architecture:  Unknown/Multiple
Operating System:  POSIX       |       Difficulty:  Easy (less than 1 hour)
 Type of failure:              |       Blocked By:
  None/Unknown                 |  Related Tickets:
       Test Case:              |
        Blocking:              |
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Comment (by rwbarton):

 Wow, nice catch!

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9271#comment:1>
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