Check upper bounds of type arguments when allocating objects of a generic type

tests/language/generic_test.dart

 // Copyright (c) 2011, 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=--enable_type_checks --enable_asserts
 //
 // Dart test program testing generic type allocations and generic type tests.
 
 class A {
   const A();
 }
@@ skipping 38 matching lines @@
     Expect.equals(true, d.caa_.b_.isT(const AA()));
     C c = new C(const AA());  // c is of raw type C, T in C<T> is Dynamic.
     Expect.equals(true, c.b_ is B);
     Expect.equals(true, c.b_ is B<AA>);
     Expect.equals(true, c.b_.isT(const AA()));
     Expect.equals(true, c.b_.isT(const AX()));
     try {
       E e = new E();  // Throws a type error, if type checks are enabled.
     } catch (TypeError error) {
       result = 1;
-      // TODO(regis): The error below is detected too late.
-      // It should be reported on line 31, at new B<T>(), i.e. new B<AX>().
-      // This will be detected when we check the subtyping constraints.
-      Expect.equals("A", error.dstType);
-      Expect.equals("AX", error.srcType);
       int pos = error.url.lastIndexOf("/", error.url.length);
       if (pos == -1) {
         pos = error.url.lastIndexOf("\\", error.url.length);
       }
       String subs = error.url.substring(pos + 1, error.url.length);
       Expect.equals("generic_test.dart", subs);
-      Expect.equals(23, error.line);
-      Expect.equals(23, error.column);
+      Expect.equals(31, error.line);  // new B<T>(t); AX does not extend A.
+      Expect.equals(17, error.column);
     }
     return result;
   }
 
   static testMain() {
     Expect.equals(1, test());
   }
 }
 
 
 main() {
   GenericTest.testMain();
 }