[GHC] #14170: 8.2.1 regression: GHC fails to simplify `natVal`

[GHC]

#14170: 8.2.1 regression: GHC fails to simplify `natVal`
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        Reporter:  vagarenko         |                Owner:  Bodigrim
            Type:  bug               |               Status:  patch
        Priority:  high              |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4212
       Wiki Page:                    |
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Comment (by darchon):

 I would really like this patch to land in 8.6.1 as our Clash Haskell-to-
 Hardware compiler has to work a lot harder with these unsimplified
 naturals. I just saw that a 8.6 branch was created on git, hence why I'm
 posting now. Patch D4212 seems to have gotten the OKs, what still needs to
 happen to it before it lands in HEAD and can end up in the 8.6 branch?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14170#comment:15>
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