fix(cl): fill cross-package unexported method Ifn/Tfn so itab is complete

_demo/go/ifaceprom-1599/foo/foo.go

@@ -0,0 +1,14 @@
+package foo
+
+type Gamer interface {
+	initGame()
+	Load()
+}
+
+type Game struct{}
+
+func (g *Game) initGame() {}
+
+func (g *Game) Load() {
+	println("load")
+}

_demo/go/ifaceprom-1599/main.go

@@ -0,0 +1,25 @@
+package main
+
+import "github.com/goplus/llgo/_demo/go/ifaceprom-1599/foo"
+
+type Game1 struct {
+	*foo.Game
+}
+
+type Game2 struct {
+}
+
+func (p *Game2) initGame() {
+}
+
+func main() {
+	var g1 any = &Game1{&foo.Game{}}
+	var g2 any = &Game2{}
+	v1, ok := g1.(foo.Gamer)
+	println("OK", v1, ok)
+	if ok {
+		v1.Load()
+	}
+	v2, ok := g2.(foo.Gamer)
+	println("FAIL", v2, ok)
+}