fix: revert deleted make targets

Makefile

@@ -64,6 +64,16 @@ ${install_bins_targets}: ${install_dir}/bin/%: ${build_dir}/${tst_dir}/%
 	@mkdir -p $(dir $@)
 	install $^ $@
 
+PHONY += graphs
+graphs:
+	cd graphs && bash generate_graphs.sh
+
+PHONY += valgrind
+valgrind: ${valgrind_targets}
+
+PHONY += ${valgrind_targets}
+${valgrind_targets}: valgrind_%: ${build_dir}/${tst_dir}/%
+	valgrind $^ ${check_argv} --leak-check=full --show-reachable=yes --track-origins=yes
 
 PHONY += build
 build: ${bins_target} ${build_dir}/libthread.so ${build_dir}/libthread.a ${build_dir}/${tst_dir}/51-fibonacci ${build_dir}/${tst_dir}/71-preemption