[committed] correct mingw32 host build error

[Catherine Moore]

I committed this patch (approved off-list by Mark Mitchell) to correct a build problem for mingw32 
hosts.

2008-03-13  Catherine Moore  <clm@codesourcery.com>

        gcc/
        *  gcc/config/i386/x-mingw32 (host-mingw32.o): Replace
        diagnostic.h with $(DIAGNOSTIC_H).


Index: config/i386/x-mingw32
===================================================================
--- config/i386/x-mingw32       (revision 144840)
+++ config/i386/x-mingw32       (working copy)
@@ -8,6 +8,6 @@ local_includedir=$(libsubdir)/$(unlibsub
  WERROR_FLAGS += -Wno-format

  host-mingw32.o : $(srcdir)/config/i386/host-mingw32.c $(CONFIG_H) $(SYSTEM_H) \
-  coretypes.h hosthooks.h hosthooks-def.h toplev.h diagnostic.h $(HOOKS_H)
+  coretypes.h hosthooks.h hosthooks-def.h toplev.h $(DIAGNOSTIC_H) $(HOOKS_H)
         $(CC) -c $(ALL_CFLAGS) $(ALL_CPPFLAGS) $(INCLUDES) \
                 $(srcdir)/config/i386/host-mingw32.c