bug#5921: 23.1; OSX: Emacs 23.1.95 pretest does not compile

[Chong Yidong]

> (old) /usr/X11R6/include include files are still picked up with
> priority by the eventually used flags

Does this patch DTRT?

=== modified file 'src/Makefile.in'
*** src/Makefile.in     2010-04-01 23:08:14 +0000
--- src/Makefile.in     2010-04-10 16:11:26 +0000
***************
*** 269,275 ****
  
  /* C_SWITCH_X_SITE must come before C_SWITCH_X_MACHINE and C_SWITCH_X_SYSTEM
     since it may have -I options that should override those two.  */
! ALL_CFLAGS=-Demacs -DHAVE_CONFIG_H $(MYCPPFLAGS) -I. -I${srcdir} 
C_SWITCH_MACHINE C_SWITCH_SYSTEM C_SWITCH_X_SITE C_SWITCH_X_MACHINE 
C_SWITCH_X_SYSTEM C_SWITCH_SYSTEM_TEMACS ${CFLAGS_SOUND} ${RSVG_CFLAGS} 
${DBUS_CFLAGS} ${GCONF_CFLAGS} ${CFLAGS} @FREETYPE_CFLAGS@ @FONTCONFIG_CFLAGS@ 
@LIBOTF_CFLAGS@ @M17N_FLT_CFLAGS@ ${DEPFLAGS}
  ALL_OBJC_CFLAGS=$(ALL_CFLAGS) @GNU_OBJC_CFLAGS@
  
  .SUFFIXES: .m
--- 269,275 ----
  
  /* C_SWITCH_X_SITE must come before C_SWITCH_X_MACHINE and C_SWITCH_X_SYSTEM
     since it may have -I options that should override those two.  */
! ALL_CFLAGS=-Demacs -DHAVE_CONFIG_H $(MYCPPFLAGS) -I. -I${srcdir} 
C_SWITCH_MACHINE C_SWITCH_SYSTEM C_SWITCH_SYSTEM_TEMACS ${CFLAGS_SOUND} 
${RSVG_CFLAGS} ${DBUS_CFLAGS} ${GCONF_CFLAGS} ${CFLAGS} C_SWITCH_X_SITE 
C_SWITCH_X_MACHINE C_SWITCH_X_SYSTEM @FREETYPE_CFLAGS@ @FONTCONFIG_CFLAGS@ 
@LIBOTF_CFLAGS@ @M17N_FLT_CFLAGS@ ${DEPFLAGS}
  ALL_OBJC_CFLAGS=$(ALL_CFLAGS) @GNU_OBJC_CFLAGS@
  
  .SUFFIXES: .m