[GHC] #10726: Upgrade MingW-w64 distributions for windows

[GHC]

#10726: Upgrade MingW-w64 distributions for windows
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        Reporter:  Phyx-             |                Owner:
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:  7.10.3
       Component:  Build System      |              Version:  7.11
      Resolution:                    |             Keywords:
Operating System:  Windows           |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #9218 #9014       |  Differential Rev(s):  Phab:D1123
  #10435                             |
       Wiki Page:                    |
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Comment (by Matt):

 Replying to [comment:39 Phyx-]:
 > I guess a temporary solution to get `7.10.3` out the door is to just re-
 export everything from `mingwex` since you can't actually specify
 `-lmingwex` current.
 >
 > But I have wondered and still do why the RTS is re-exporting symbols
 like this instead of us just linking against `-lmingwex`.

 I think the main issue here is that not all symbols from `libmingwex.a`
 get linked into final ghc executable so some they can't be resolved when
 running GHC in interactive. Therefore i believe proper solution should be
 linking `libmingwex.a`as a whole archive when building ghc.exe, instead of
 just letting GCC to link only used symbols as it does by default.

 Reexporting those symbols seems like a bad idea, because, if I'm not
 mistaken, RTS gets linked into ever executable produced by GHC, so this
 way we are actually forcing possibly unnecessary symbols into every
 executable?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10726#comment:46>
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