fixes #221, initial sync*, async, async* implementation

test/codegen/expect/unittest.txt

Index: test/codegen/expect/unittest.txt
diff --git a/test/codegen/expect/unittest.txt b/test/codegen/expect/unittest.txt
new file mode 100644
index 0000000000000000000000000000000000000000..1867a525dd7de58e601654d5230c61be60def32f
--- /dev/null
+++ b/test/codegen/expect/unittest.txt
@@ -0,0 +1,17 @@
+// Messages from compiling unittest.dart
+info: [DynamicInvoke] (window as dynamic).suite(name, body) requires dynamic invoke (test/codegen/unittest.dart, line 12, col 41)
+info: [DynamicInvoke] (window as dynamic).test(name, (done) {_finishTest(f) {if (f is Future) {f.then(_finishTest);} else {done();}} _finishTest(body());}) requires dynamic invoke (test/codegen/unittest.dart, line 19, col 3)
+info: [DynamicInvoke] f.then(_finishTest) requires dynamic invoke (test/codegen/unittest.dart, line 22, col 9)
+info: [DynamicInvoke] done() requires dynamic invoke (test/codegen/unittest.dart, line 24, col 9)
+info: [DynamicCast] matcher(actual) (dynamic) will need runtime check to cast to type bool (test/codegen/unittest.dart, line 33, col 8)
+info: [DynamicInvoke] matcher(actual) requires dynamic invoke (test/codegen/unittest.dart, line 33, col 8)
+info: [DynamicInvoke] actual.length requires dynamic invoke (test/codegen/unittest.dart, line 46, col 18)
+info: [DynamicCast] equals(expected[i])(actual[i]) (dynamic) will need runtime check to cast to type bool (test/codegen/unittest.dart, line 48, col 14)
+info: [DynamicInvoke] equals(expected[i])(actual[i]) requires dynamic invoke (test/codegen/unittest.dart, line 48, col 14)
+info: [DynamicInvoke] actual[i] requires dynamic invoke (test/codegen/unittest.dart, line 48, col 34)
+info: [DynamicCast] matcher(actual) (dynamic) will need runtime check to cast to type bool (test/codegen/unittest.dart, line 60, col 23)
+info: [DynamicInvoke] matcher(actual) requires dynamic invoke (test/codegen/unittest.dart, line 60, col 23)
+info: [DynamicInvoke] actual < expected requires dynamic invoke (test/codegen/unittest.dart, line 68, col 43)
+info: [DynamicInvoke] actual > expected requires dynamic invoke (test/codegen/unittest.dart, line 69, col 46)
+info: [DynamicInvoke] actual() requires dynamic invoke (test/codegen/unittest.dart, line 75, col 7)
+info: [DynamicInvoke] matcher(e) requires dynamic invoke (test/codegen/unittest.dart, line 78, col 14)