Support async/await in dart2dart.

tests/language/async_await_syntax_test.dart

-// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2015, 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 async/await syntax.
 
+import 'dart:async';

[floitsch, 2015/02/02 14:19:09]

show Stream

+
 var yield = 0;
 var await = 0;
+get st => new Stream.fromIterable([]);
 
 a01a() async => null;                        /// a01a: ok
 a01b() async* => null;                       /// a01b: compile-time error
 a01c() sync* => null;                        /// a01c: compile-time error
 a02a() async {}                              /// a02a: ok
 a03a() async* {}                             /// a03a: ok
 a03b() async * {}                            /// a03b: compile-time error
 a04a() sync* {}                              /// a04a: ok
 a04b() sync {}                               /// a04b: compile-time error
 a04c() sync * {}                             /// a04c: compile-time error
@@ skipping 11 matching lines @@
   await(0);                                  /// a05d: continued
 }                                            /// a05d: continued
 a05e() {                                     /// a05e: ok
   await(a) {}                                /// a05e: continued
   await(0);                                  /// a05e: continued
 }                                            /// a05e: continued
 a05f() async {                               /// a05f: compile-time error
   var await = (a) {};                        /// a05f: continued
   await(0);                                  /// a05f: continued
 }                                            /// a05f: continued
-a06a() async { await for (var o in []) {} }  /// a06a: ok
-a06b() sync* { await for (var o in []) {} }  /// a06b: compile-time error
+a06a() async { await for (var o in st) {} }  /// a06a: ok
+a06b() sync* { await for (var o in st) {} }  /// a06b: compile-time error
 a07a() sync* { yield 0; }                    /// a07a: ok
 a07b() sync { yield 0; }                     /// a07b: compile-time error
 a08a() sync* { yield* []; }                  /// a08a: ok
 a08b() sync { yield 0; }                     /// a08b: compile-time error
 a09a() async* { yield 0; }                   /// a09a: ok
 a10a() async* { yield* []; }                 /// a10a: ok
 
 get sync sync {}                             /// a11a: compile-time error
 get sync sync* {}                            /// a11b: ok
 get async async {}                           /// a11c: ok
@@ skipping 45 matching lines @@
   b00d() {}   /// b00d: continued
 
   b01a() async => null;                        /// b01a: ok
   b01b() async* => null;                       /// b01b: compile-time error
   b01c() sync* => null;                        /// b01c: compile-time error
   b02a() async {}                              /// b02a: ok
   b03a() async* {}                             /// b03a: ok
   b04a() sync* {}                              /// b04a: ok
   b04b() sync {}                               /// b04b: compile-time error
   b05a() async { await 0; }                    /// b05a: ok
-  b06a() async { await for (var o in []) {} }  /// b06a: ok
+  b06a() async { await for (var o in st) {} }  /// b06a: ok
   b06b() async { await for ( ; ; ) {} }        /// b06b: compile-time error
   b07a() sync* { yield 0; }                    /// b07a: ok
   b08a() sync* { yield* []; }                  /// b08a: ok
   b09a() async* { yield 0; }                   /// b09a: ok
   b10a() async* { yield* []; }                 /// b10a: ok
 
   get sync sync {}                             /// b11a: compile-time error
   get sync sync* {}                            /// b11b: ok
   get async async {}                           /// b11c: ok
   get async async* {}                          /// b11d: ok
@@ skipping 21 matching lines @@
 
 method1() {
   c01a() async => null; c01a();                        /// c01a: ok
   c01b() async* => null; c01b();                       /// c01b: compile-time error
   c01c() sync* => null; c01c();                        /// c01c: compile-time error
   c02a() async {} c02a();                              /// c02a: ok
   c03a() async* {} c03a();                             /// c03a: ok
   c04a() sync* {} c04a();                              /// c04a: ok
   c04b() sync {} c04b();                               /// c04b: compile-time error
   c05a() async { await 0; } c05a();                    /// c05a: ok
-  c06a() async { await for (var o in []) {} } c06a();  /// c06a: ok
+  c06a() async { await for (var o in st) {} } c06a();  /// c06a: ok
   c07a() sync* { yield 0; } c07a();                    /// c07a: ok
   c08a() sync* { yield* []; } c08a();                  /// c08a: ok
   c09a() async* { yield 0; } c09a();                   /// c09a: ok
   c10a() async* { yield* []; } c10a();                 /// c10a: ok
 }
 
 method2() {
   var d01a = () async => null; d01a();                         /// d01a: ok
   var d01b = () async* => null; d01b();                        /// d01b: compile-time error
   var d01c = () sync* => null; d01c();                         /// d01c: compile-time error
   var d02a = () async {}; d02a();                              /// d02a: ok
   var d03a = () async* {}; d03a();                             /// d03a: ok
   var d04a = () sync* {}; d04a();                              /// d04a: ok
   var d04b = () sync {}; d04b();                               /// d04b: compile-time error
   var d05a = () async { await 0; }; d05a();                    /// d05a: ok
-  var d06a = () async { await for (var o in []) {} }; d06a();  /// d06a: ok
+  var d06a = () async { await for (var o in st) {} }; d06a();  /// d06a: ok
   var d07a = () sync* { yield 0; }; d07a();                    /// d07a: ok
   var d08a = () sync* { yield* []; }; d08a();                  /// d08a: ok
   var d08b = () sync* { yield*0+1; }; d08b();                  /// d08b: ok
   var d08c = () { yield*0+1; }; d08c();                        /// d08c: ok
   var d09a = () async* { yield 0; }; d09a();                   /// d09a: ok
   var d10a = () async* { yield* []; }; d10a();                 /// d10a: ok
 }
 
 
 void main() {
@@ skipping 88 matching lines @@
   a = c.async;  /// b14c: continued
   a = c.async;  /// b14d: continued
   c.sync();     /// b15a: continued
   c.sync();     /// b15b: continued
   c.async();    /// b15c: continued
   c.async();    /// b15d: continued
 
   method1();
   method2();
 }