Add initial parser support for harmony iteration

src/typing.cc

Index: src/typing.cc
diff --git a/src/typing.cc b/src/typing.cc
index 3e4144e68b63261d8e66585fd4b2db87c328eddc..4ba67213a1301edc78c5d6b4232c2f753a759bac 100644
--- a/src/typing.cc
+++ b/src/typing.cc
@@ -224,6 +224,13 @@ void AstTyper::VisitForInStatement(ForInStatement* stmt) {
 }
 
 
+void AstTyper::VisitForOfStatement(ForOfStatement* stmt) {
+  ASSERT(!HasStackOverflow());
+  CHECK_ALIVE(Visit(stmt->iterable()));
+  CHECK_ALIVE(Visit(stmt->body()));
+}
+
+
 void AstTyper::VisitTryCatchStatement(TryCatchStatement* stmt) {
   ASSERT(!HasStackOverflow());
   CHECK_ALIVE(Visit(stmt->try_block()));