add silient, ignore_error and silent_ignore_error
diff --git a/test/silent_ignore_error.mk b/test/silent_ignore_error.mk
new file mode 100644
index 0000000..1c52d5e
--- /dev/null
+++ b/test/silent_ignore_error.mk
@@ -0,0 +1,3 @@
+test:
+	-@false
+	@-false