Update the Windows build according to 2011-02-08T21:42:56Z!tromey@redhat.com and...

Update the Windows build according to 2011-02-08T21:42:56Z!tromey@redhat.com and 2011-02-09T17:04:43Z!schwab@linux-m68k.org.

 src/makefile.w32-in (GLOBAL_SOURCES, SOME_MACHINE_OBJECTS, obj): New
 macros.
 (globals.h, gl-stamp): New targets.
 (clean): Clean gl-stamp and globals.h.
 nt/makefile.w32-in (bootstrap-nmake, bootstrap-gmake): Make the
 "make-docfile" target in lib-src, before bootstrapping the src
 directory.  Needed since building in src needs to run make-docfile
 to produce globals.h.