[VM generic function types] Properly set the scope function after parsing a

tests/language_2/generic_methods_generic_function_result_test.dart

+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+//
+// VMOptions=--generic-method-syntax,--error-on-bad-type
+
+// Verify that function type parameter S can be resolved in bar.
+
+import "package:expect/expect.dart";
+
+T foo<T extends num>(int i, T t) => i + t;
+
+List<T Function<T extends num>(S, T)> bar<S extends num>() {
+  return <T Function<T extends num>(S, T)>[foo, foo];
+}
+
+void main() {
+  var list = bar<int>();
+  print(list[0]
+      .runtimeType); // "(int, int) => int" when reifying generic functions.
+  Expect.equals(123, list[1]<int>(100, 23));
+}