Fix evaluating in async/sync*/async* methods.

runtime/observatory/tests/service/evaluate_in_sync_star_activation_test.dart

+// Copyright (c) 2016, 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 'dart:async';
+import 'dart:developer';
+import 'package:observatory/service_io.dart';
+import 'package:unittest/unittest.dart';
+import 'service_test_common.dart';
+import 'test_helper.dart';
+
+generator() sync* {
+  var x = 3;
+  var y = 4;
+  debugger();
+  yield y;
+  var z = x + y;
+  debugger();
+  yield z;
+}
+
+testFunction() {
+  for (var ignored in generator());
+}
+
+var tests = [
+
+hasStoppedAtBreakpoint,
+
+(Isolate isolate) async {
+  // Make sure we are in the right place.
+  var stack = await isolate.getStack();
+  var topFrame = 0;
+  expect(stack.type, equals('Stack'));
+  expect(await stack['frames'][topFrame].location.getLine(), 16);
+
+  var result = await isolate.evalFrame(topFrame, "x");
+  print(result);
+  expect(result.valueAsString, equals("3"));
+},
+
+resumeIsolate,
+
+hasStoppedAtBreakpoint,
+
+(Isolate isolate) async {
+  // Make sure we are in the right place.
+  var stack = await isolate.getStack();
+  var topFrame = 0;
+  expect(stack.type, equals('Stack'));
+  expect(await stack['frames'][topFrame].location.getLine(), 19);
+
+  var result = await isolate.evalFrame(topFrame, "z");
+  print(result);
+  expect(result.valueAsString, equals("7"));
+},
+
+resumeIsolate,
+
+];
+
+main(args) => runIsolateTests(args, tests, testeeConcurrent: testFunction);