initial sync*, part of #221

test/codegen/expect/syncstar_yield_test.js

+dart_library.library('syncstar_yield_test', null, /* Imports */[
+  "dart_runtime/dart",
+  'dart/core',
+  'expect'
+], /* Lazy imports */[
+], function(exports, dart, core, expect) {
+  'use strict';
+  let dartx = dart.dartx;
+  function* foo1() {
+    yield 1;
+  }
+  dart.fn(foo1, core.Iterable$(core.int), []);
+  function* foo2(p) {
+    let t = false;
+    yield null;
+    while (true) {
+      a:
+        for (let i = 0; dart.notNull(i) < dart.notNull(dart.as(p, core.num)); i = dart.notNull(i) + 1) {
+          if (!dart.notNull(t)) {
+            for (let j = 0; dart.notNull(j) < 3; j = dart.notNull(j) + 1) {
+              yield -1;
+              t = true;
+              break a;
+            }
+          }
+          yield i;
+        }
+    }
+  }
+  dart.fn(foo2, core.Iterable$(core.int), [dart.dynamic]);
+  function* foo3(p) {
+    let i = 0;
+    i = dart.notNull(i) + 1;
+    p = dart.notNull(p) + 1;
+    yield dart.notNull(p) + dart.notNull(i);
+  }
+  dart.fn(foo3, core.Iterable$(core.int), [core.int]);
+  function main() {
+    expect.Expect.listEquals([1], foo1()[dartx.toList]());
+    expect.Expect.listEquals([null, -1, 0, 1, 2, 3, 0, 1, 2, 3], foo2(4)[dartx.take](10)[dartx.toList]());
+    let t = foo3(0);
+    let it1 = t[dartx.iterator];
+    let it2 = t[dartx.iterator];
+    it1.moveNext();
+    it2.moveNext();
+    expect.Expect.equals(2, it1.current);
+    expect.Expect.equals(2, it2.current);
+    expect.Expect.isFalse(it1.moveNext());
+    expect.Expect.isFalse(it1.moveNext());
+    expect.Expect.isFalse(it2.moveNext());
+    expect.Expect.isFalse(it2.moveNext());
+  }
+  dart.fn(main);
+  // Exports:
+  exports.foo1 = foo1;
+  exports.foo2 = foo2;
+  exports.foo3 = foo3;
+  exports.main = main;
+});