ssa: fix named func call

cl/_testgo/closure/in.go

@@ -0,0 +1,15 @@
+package main
+
+type T func(n int)
+
+func main() {
+	var env string = "env"
+	var v1 T = func(i int) {
+		println("func", i)
+	}
+	var v2 T = func(i int) {
+		println("closure", i, env)
+	}
+	v1(100)
+	v2(200)
+}