Followup, bug 350211 - xpcom and js are separate tiers now, not a single "core" tier

Makefile.in

@@ -90,9 +90,10 @@ endif
 
 include $(topsrcdir)/config/rules.mk
 
-# After we build tier toolki, go back and build the tools from previous dirs
+# After we build tier toolkit, go back and build the tools from previous dirs
 tier_toolkit::
-	$(MAKE) tools_tier_core
+	$(MAKE) tools_tier_js
+	$(MAKE) tools_tier_xpcom
 	$(MAKE) tools_tier_gecko
 	$(MAKE) tools_tier_toolkit