[GHC] #8767: Add rules involving `coerce` to the libraries

[GHC]

#8767: Add rules involving `coerce` to the libraries
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              Reporter:  nomeata     |            Owner:  ekmett
                  Type:  task        |           Status:  new
              Priority:  normal      |        Milestone:  7.10.1
             Component:  Core        |          Version:  7.9
  Libraries                          |         Keywords:
            Resolution:              |     Architecture:  Unknown/Multiple
      Operating System:              |       Difficulty:  Unknown
  Unknown/Multiple                   |       Blocked By:  8718
       Type of failure:              |  Related Tickets:  #2110
  None/Unknown                       |
             Test Case:              |
  tests/simplCore/should_run/T2110.hs|
              Blocking:              |
Differential Revisions:              |
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Changes (by thomie):

 * cc: dfeuer, core-libraries-committee@… (added)


Comment:

 {{{
 commit 603b7be7bd3abaf0e2c210e8d9015b1d613b4715
 Author: David Feuer <David.Feuer at gmail.com>
 Date:   Thu Nov 13 21:12:05 2014 +0100

     Implement amap/coerce for Array (re #9796)

     Implement an `amap`/`coerce` rule in `GHC.Arr` to match the
     `map`/`coerce` rule in GHC.Base.

     In order to do so, delay inlining `amap` until phase 1.

     To prevent the inlining delay from causing major inefficiencies due to
     missed list fusion, rewrite `amap` to avoid relying on list fusion.
 This
     has the extra benefit of reducing the size of the compiled amap code
 by
     skipping the impossible case of an array with a negative size.

     Reviewed By: nomeata

     Differential Revision: https://phabricator.haskell.org/D471
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8767#comment:24>
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