Fix make exiting 1 if test script is missing

.make-and-exec-Makefile

@@ -1,4 +1,4 @@
 .make-and-exec-binaries/%: %.c
 	mkdir -p .make-and-exec-binaries
 	$(CC) -O3 -o $@ $< $(CFLAGS)
-	[ -f ./.$(notdir $(@))-test ] && ./.$(notdir $(@))-test
+	[ -f ./.$(notdir $(@))-test ] && ./.$(notdir $(@))-test || true