Add spread rewriting

src/parsing/parameter-initializer-rewriter.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/parsing/parameter-initializer-rewriter.h"
 
 #include "src/ast/ast.h"
 #include "src/ast/ast-expression-visitor.h"
 #include "src/ast/scopes.h"
 
@@ skipping 42 matching lines @@
       Visit(prop->key());
     }
     // No need to visit the values, since all values are functions with
     // the class scope on their scope chain.
     DCHECK(prop->value()->IsFunctionLiteral());
   }
 }
 
 
 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);
   }
 }
 
 
 }  // anonymous namespace
 
 
 void RewriteParameterInitializerScope(uintptr_t stack_limit,
                                       Expression* initializer, Scope* old_scope,
                                       Scope* new_scope) {
   Rewriter rewriter(stack_limit, initializer, old_scope, new_scope);
   rewriter.Run();
 }
 
 
 }  // namespace internal
 }  // namespace v8