Add parser support for generators.

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
index e1326722b531303ee73ed11a532b4a953698593d..33ce236462e00bd6727311e2163cceb8650ab071 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -190,6 +190,7 @@ void Scope::SetDefaults(ScopeType type,
   illegal_redecl_ = NULL;
   scope_inside_with_ = false;
   scope_contains_with_ = false;
+  scope_inside_generator_ = false;
   scope_calls_eval_ = false;
   // Inherit the strict mode from the parent scope.
   language_mode_ = (outer_scope != NULL)
@@ -320,6 +321,7 @@ void Scope::Initialize() {
   if (outer_scope_ != NULL) {
     outer_scope_->inner_scopes_.Add(this, zone());
     scope_inside_with_ = outer_scope_->scope_inside_with_ || is_with_scope();
+    scope_inside_generator_ = outer_scope_->inside_generator();
   } else {
     scope_inside_with_ = is_with_scope();
   }