move out c/cpp/py

cl/_testdata/method/in.go

@@ -0,0 +1,19 @@
+package main
+
+import _ "unsafe"
+
+type T int
+
+func (a T) Add(b T) T {
+	return a + b
+}
+
+//go:linkname printf C.printf
+func printf(format *int8, __llgo_va_list ...any)
+
+var format = [...]int8{'H', 'e', 'l', 'l', 'o', ' ', '%', 'd', '\n', 0}
+
+func main() {
+	a := T(1)
+	printf(&format[0], a.Add(2))
+}