ssa: set method.name to pkg.name if private

cl/internal/foo/foo.go

@@ -16,3 +16,18 @@ type Foo struct {
 func (v Foo) Pb() *byte {
 	return v.pb
 }
+
+type Gamer interface {
+	initGame()
+	Load()
+}
+
+type Game struct {
+}
+
+func (g *Game) initGame() {
+}
+
+func (g *Game) Load() {
+	println("load")
+}