Compile Makefile-free dependencies with +debug_info only

As much as I dislike this change, this should simplify the
process of moving to erlang.mk.

core/deps.mk

@@ -34,7 +34,7 @@ deps:: $(ALL_DEPS_DIRS)
 		if [ -f $$dep/GNUmakefile ] || [ -f $$dep/makefile ] || [ -f $$dep/Makefile ] ; then \
 			$(MAKE) -C $$dep ; \
 		else \
-			echo "include $(CURDIR)/erlang.mk" | $(MAKE) -f - -C $$dep ; \
+			echo "include $(CURDIR)/erlang.mk" | ERLC_OPTS=+debug_info $(MAKE) -f - -C $$dep ; \
 		fi ; \
 	done
 

erlang.mk

@@ -108,7 +108,7 @@ deps:: $(ALL_DEPS_DIRS)
 		if [ -f $$dep/GNUmakefile ] || [ -f $$dep/makefile ] || [ -f $$dep/Makefile ] ; then \
 			$(MAKE) -C $$dep ; \
 		else \
-			echo "include $(CURDIR)/erlang.mk" | $(MAKE) -f - -C $$dep ; \
+			echo "include $(CURDIR)/erlang.mk" | ERLC_OPTS=+debug_info $(MAKE) -f - -C $$dep ; \
 		fi ; \
 	done