Prevent expensive and unnecessary error formatting in the case a bound check is

tests/language/f_bounded_quantification3_test.dart

+// Copyright (c) 2013, 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.
+
+// Test for F-Bounded Quantification.
+
+class FBound1<F1 extends FBound1<F1, F2>, F2 extends FBound2<F1, F2>> {
+  Test() {
+    new FBound1<F1, F2>();
+    new FBound2<F1, F2>();
+  }
+}
+
+class FBound2<F1 extends FBound1<F1, F2>, F2 extends FBound2<F1, F2>> {
+  Test() {
+    new FBound1<F1, F2>();
+    new FBound2<F1, F2>();
+  }
+}
+
+class Bar extends FBound1<Bar, Baz> {}
+
+class Baz extends FBound2<Bar, Baz> {}
+
+main() {
+  new FBound1<Bar, Baz>().Test();
+  new FBound2<Bar, Baz>().Test();
+}