bug#18302: MSYS2 build issues

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 22 Aug 2014 16:18:11 +0200
> From: Karol Ostrovsky <karol.ostrovsky@gmail.com>
> Cc: Ken Brown <kbrown@cornell.edu>, Chris Zheng <chriszheng99@gmail.com>, 18302@debbugs.gnu.org
> 
> I will try to summarise the situation, and I am attaching my updated
> solution proposal for this particular bug:
> 
> 1. MSYS2 uname must be handled properly, and that is fixed in the new
> proposed patch.  I disagree with not renaming opsys from mingw32 to
> mingw, since mingw32 string is used in other places in the same file
> and it means something else there, which I find possibly confusing.
> But this change is not in my new patch.
> 
> 2. -mtune is back to what it was with a minimal change required for
> MSYS2+MinGW-w64 uname handling.
> 
> 3. Include path for xpm in MSYS2+MinGW-w64 is handled in the same way
> as in Cygwin.  Perhaps, the same type of comment as was added for
> Cygwin should be added for MSYS2+MinGW-w64.
> 
> 4. A loop is added in the recipe for emacs.exe to handle
> bootstrap-emacs.exe busy problem.

Thanks.  I installed items 1, 2, and 4, but not item 3.

If you think we should do something about the xpm.h header, then
please try this alternative solution: copy the xpm.h header file into
the X11 subdirectory of your GCC 'include' directory (the one where
you have all the standard C header files), then try configuring and
building Emacs without adding the "-I/mingw64/include/noX" switch to
CPPFLAGS.  If that doesn't work, please show the error messages you
get from the compiler, and let's take it from there.

If, for some reason, you think that copying xpm.h to include/X11/xpm.h
is not appropriate, please explain why you think so.