[GHC] #9390: Inlining prevents evaluation of ignored parts of unboxed tuples

[GHC]

#9390: Inlining prevents evaluation of ignored parts of unboxed tuples
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              Reporter:  snoyberg    |            Owner:
                  Type:  bug         |           Status:  merge
              Priority:  normal      |        Milestone:  7.8.4
             Component:  Compiler    |          Version:  7.8.3
            Resolution:              |         Keywords:
      Operating System:  Linux       |     Architecture:  x86_64 (amd64)
       Type of failure:  Incorrect   |       Difficulty:  Unknown
  result at runtime                  |       Blocked By:
             Test Case:              |  Related Tickets:
  simplCore/should_run/T9390         |
              Blocking:              |
Differential Revisions:              |
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Comment (by simonmar):

 I agree that the memo table implementation is relying in a very delicate
 way on a particular order of evaluation, so I'd be fine with using an
 explicit `lazy` in the implementation of memo and removing it from
 `unsafeDupablePerformIO`.  If you want to do this and all the tests pass,
 it's fine by me.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9390#comment:34>
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