Bug 847369 - Hook up js/src to check make target; r=glandium

This is a regression from bug 784841.

Makefile.in

@@ -173,3 +173,10 @@ scheck::
 endif
 
 js/src/Makefile: subsrcdir := js/src
+
+ifdef ENABLE_TESTS
+# Incorporate static tier directories into tests. This should be incorporated
+# into moz.build files someday.
+check::
+	$(call SUBMAKE,$@,js/src)
+endif