[GHC] #15570: Core transformations generate bad indexCharOffAddr# call

[GHC]

#15570: Core transformations generate bad indexCharOffAddr# call
-------------------------------------+-------------------------------------
        Reporter:  alpmestan         |                Owner:  alpmestan
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.6.1
       Component:  Compiler          |              Version:  8.5
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #15286            |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by alpmestan):

 I wrote https://ghc.haskell.org/trac/ghc/ticket/15286#comment:7 to report
 that I have a PR up to get rid of those `-O0`s, implementing hsyl20's
 recommendation, and that it works! (It even fixes some failing tests.)

 I'm about to turn off my computer, but I guess I can try building our
 little example from the ticket description tomorrow, using GHC&libs built
 by hadrian without those `-O0`s, reporting back on the generated Core
 here.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15570#comment:16>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler