[GHC] #12173: foldl' semantics changed from 4.7 to 4.8

[GHC]

#12173: foldl' semantics changed from 4.7 to 4.8
-------------------------------------+-------------------------------------
        Reporter:  dfeuer            |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Core Libraries    |              Version:  7.10.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Runtime crash     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by dfeuer):

 I should clarify that I'm not personally attached to either option. But
 the semantic change was not discussed, I suspect it was accidental, and it
 is inconsistent with `Foldable` defaults. I feel pretty strongly that
 there should only be ''one'' notion of `foldl'` in `base`, whichever that
 is.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12173#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler