move out c/cpp/py

cl/_testrt/concat/in.go

@@ -0,0 +1,17 @@
+package main
+
+func concat(args ...string) (ret string) {
+	for _, v := range args {
+		ret += v
+	}
+	return
+}
+
+func info(s string) string {
+	return "" + s + "..."
+}
+
+func main() {
+	result := concat("Hello", " ", "World")
+	println(result)
+}