Add stackTrace to Error object.

tests/corelib/error_stack_trace_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.
+
+import "package:expect/expect.dart";
+
+void argument() {
+  throw new ArgumentError(499);
+}
+
+void noSuchMethod() {
+  (499).doesNotExist();
+}
+
+void nullThrown() {
+  throw null;
+}
+
+void range() {
+  throw new RangeError.range(0, 1, 2);
+}
+
+void fallThrough() {
+  nested() {}
+
+  switch (5) {
+    case 5:
+      nested();
+    default:
+      Expect.fail("Should not reach");
+  }
+}
+
+abstract class A {
+  foo();
+}
+
+void abstractClassInstantiation() {
+  new A();
+}
+
+void unsupported() {
+  throw new UnsupportedError("unsupported");
+}
+
+void unimplemented() {
+  throw new UnimplementedError("unimplemented");
+}
+
+void state() {
+  return [1, 2].single;
+}
+
+void type() {
+  return 1 + "string";
+}
+
+main() {
+  List<Function> errorFunctions = [
+      argument, noSuchMethod, nullThrown, range, fallThrough,
+      abstractClassInstantiation, unsupported, unimplemented, state,
+      type ];
+
+  for (var f in errorFunctions) {
+    bool hasThrown = false;
+    try {
+      f();
+    } catch(e) {
+      hasThrown = true;
+      Expect.isTrue(e.stackTrace is StackTrace,
+                    "$e doesn't have a non-null stack trace");
+    }
+    Expect.isTrue(hasThrown);
+  }
+}