[GHC] #8842: Make sure msys2 builds non emulating binaries

[GHC]

#8842: Make sure msys2 builds non emulating binaries
-------------------------------------+-------------------------------------
        Reporter:  schyler           |                   Owner:
            Type:  task              |                  Status:  infoneeded
        Priority:  normal            |               Milestone:  7.12.1
       Component:  Build System      |                 Version:  7.8.1-rc2
      Resolution:                    |                Keywords:  msys2
Operating System:  Windows           |            Architecture:
 Type of failure:  None/Unknown      |  Unknown/Multiple
      Blocked By:                    |               Test Case:
 Related Tickets:                    |                Blocking:
                                     |  Differential Revisions:
-------------------------------------+-------------------------------------
Changes (by thomie):

 * status:  new => infoneeded
 * milestone:   => 7.12.1


Comment:

 On Windows, GHC uses a mingw gcc compiler. This command shows that it does
 define the `_WIN32` macro:
 {{{
 $ /opt/ghc-7.8.3/mingw/bin/gcc -dM -E -x c /dev/null | grep ' _WIN32'
 #define _WIN32 1
 }}}

 I also compiled a small c program containing an `#ifdef _WIN32` block on
 Windows using `ghc -c`, and it indeed showed that `_WIN32` is defined.

 The [wiki:Building/Preparation/Windows build instruction on Windows] for
 GHC itself are also pretty clear to use the non-emulating version of
 MSYS2.

 Anything else I can do to check this?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8842#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler