Track our dependencies properly by exporting before checking dependencies

client.mak

@@ -339,6 +339,7 @@ depend:
 	set DIST_DIRS=1
 	set LAYOUT_DIRS=1
 	set CLIENT_DIRS=1
+	nmake -f makefile.win export
 	nmake -f makefile.win depend 
 
 depend_xpconnect:

client.mk

@@ -541,7 +541,7 @@ endif
 # Depend
 
 depend:: $(OBJDIR)/Makefile $(OBJDIR)/config.status
-	$(MOZ_MAKE) $@;
+	$(MOZ_MAKE) export && $(MOZ_MAKE) depend
 
 ####################################
 # Build it