Add some tests for calls with checks in strong mode.

tests/language_strong/covariant_subtyping_tearoff2_test.dart

Index: tests/language_strong/covariant_subtyping_tearoff2_test.dart
diff --git a/tests/language_strong/covariant_subtyping_unsafe_call2_test.dart b/tests/language_strong/covariant_subtyping_tearoff2_test.dart
similarity index 72%
copy from tests/language_strong/covariant_subtyping_unsafe_call2_test.dart
copy to tests/language_strong/covariant_subtyping_tearoff2_test.dart
index ea5920384df7cd4e5a73ecfb0d1595d2e5090864..306d83ddf6d9863f66067ece1969bbce12705d29 100644
--- a/tests/language_strong/covariant_subtyping_unsafe_call2_test.dart
+++ b/tests/language_strong/covariant_subtyping_tearoff2_test.dart
@@ -4,18 +4,23 @@
 import 'package:expect/expect.dart';
 
 class Implementation {
-  method(int x) {}
+  dynamic method(int x) {}
 }
 
 abstract class Interface<T> {
-  method(T x);
+  dynamic method(T x);
 }
 
 class Subclass extends Implementation implements Interface<int> {}
 
+typedef dynamic TakeNum(num x);
+
 main() {
   Subclass subclass = new Subclass();
   Interface<int> intInterface = subclass;
   Interface<num> numInterface = intInterface;
-  Expect.throws(() => numInterface.method(2.5));
+  TakeNum f = numInterface.method;
+  Expect.throws(() => f(2.5));
+  dynamic f2 = f;
+  Expect.throws(() => f2(2.5));
 }