Add spread rewriting

src/parsing/parameter-initializer-rewriter.cc

Index: src/parsing/parameter-initializer-rewriter.cc
diff --git a/src/parsing/parameter-initializer-rewriter.cc b/src/parsing/parameter-initializer-rewriter.cc
index eaf1889392086294270d5526163d4d33c080a866..978fa740f62e01e6163644a1d8554fbf85d46919 100644
--- a/src/parsing/parameter-initializer-rewriter.cc
+++ b/src/parsing/parameter-initializer-rewriter.cc
@@ -60,8 +60,16 @@ void Rewriter::VisitClassLiteral(ClassLiteral* class_literal) {
 
 
 void Rewriter::VisitVariableProxy(VariableProxy* proxy) {
-  DCHECK(!proxy->is_resolved());
-  if (old_scope_->RemoveUnresolved(proxy)) {
+  // TODO(nikolaos): This is the point that I'm not sure whether I have
+  // done the right thing (changing the scope of temporary variables).
+  if (proxy->is_resolved()) {
+    Variable* var = proxy->var();
+    DCHECK_EQ(var->mode(), TEMPORARY);
+    if (old_scope_->RemoveTemporary(var)) {
+      var->set_scope(new_scope_);
+      new_scope_->AddTemporary(var);
+    }
+  } else if (old_scope_->RemoveUnresolved(proxy)) {
     new_scope_->AddUnresolved(proxy);
   }
 }