[GHC] #9567: tc124 fails as '*** Core Lint errors : in result of Simplifier ***' in WAY=optasm

[GHC]

#9567: tc124 fails as '*** Core Lint errors : in result of Simplifier ***' in
WAY=optasm
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              Reporter:  slyfox      |            Owner:
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.9
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  x86_64 (amd64)
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:  GHC         |       Blocked By:
  rejects valid program              |  Related Tickets:
             Test Case:  tc124       |
              Blocking:              |
Differential Revisions:              |
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Comment (by slyfox):

 What is odd is it does not fail in norma mode.
 Only in the following modes (today's -HEAD):

 {{{
 Unexpected failures:
    typecheck/should_compile  tc124 [exit code non-0] (hpc,optasm,optllvm)
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9567#comment:1>
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