add usage for llgo

cmd/internal/test/test.go

@@ -21,6 +21,9 @@ func init() {
 }
 
 func runCmd(cmd *base.Command, args []string) {
+	defer func() {
+		recover()
+	}()
 	if err := cmd.Flag.Parse(args); err != nil {
 		panic(err)
 	}