[GHC] #15696: Derived Ord instance for enumerations with more than 8 elements seems to be incorrect

[GHC]

#15696: Derived Ord instance for enumerations with more than 8 elements seems to be
incorrect
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        Reporter:  mrkkrp            |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  highest           |            Milestone:  8.6.2
       Component:  Compiler          |              Version:  8.6.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5196,
       Wiki Page:                    |  Phab:D5201
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Comment (by osa1):

 Sorry it's a bit hard to follow -- I asked Simon Marlow about the
 segfault, and he correctly guessed that the problem is that primops are
 assumed to be non-allocating and I have to update `StgCmmExpr.isSimpleOp`.
 This change is included in the diff and it fixes the segfault.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15696#comment:59>
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