[AD] Cross-compiling, and related outstanding issues

[Chris <chris.kcat@xxxxxxxxxx>]

After finally getting XMinGW setup, I went to try compiling Allegro 
(updated fresh from CVS, after calling 'make veryclean') for Windows. 
After fixing some problems (xmingw related, not Allegro) I got it 
compiling. I ran './fix.sh mingw32' then './xmake.sh', and it went good 
all the way until poly3d.c where I got the familiar error:
src/poly3d.c:32:35: obj/mingw32/asmcapa.h: No such file or directory

It seems the solution was simpler than I thought:
'./xmake.sh obj/mingw32/asmcapa.h'

I also got the error:
src/i386/asmdefs.inc:29:37: obj/mingw32/asmdef.inc: No such file or 
directory

which was fixed similarly:
'./xmake.sh obj/mingw32/asmdef.inc'

It compiled all the way to creating liballeg.a where I got the error:
i386-mingw32msvc-dlltool: Can't open def file: lib/mingw32/allegro.def

Running 'misc/fixdll.sh' fixed that. It happilly compiled the examples.. 
at least until it got to datedit.c:
tools/datedit.c:115:39: obj/mingw32/plugins.h: No such file or directory

A similar fix: './xmake.sh obj/mingw32/plugins.h'

Everything else went smoothly (including su -c "./xmake.sh install").. 
well, except for test.cpp, but that's because XMinGW doesn't recognize 
the C++ compiler. Not Allegro's fault.

So, to recap, it seems these were missing in the dependancy chain:
obj/mingw32/asmcapa.h
obj/mingw32/asmdef.inc
obj/mingw32/plugins.h

and this needs to be run for lib/mingw32/allegro.def: misc/fixdll.sh. I 
suppose this latter-most point is only done for the packaged releases, 
though.