Revert "Merge arguments branch to bleeding merge."

src/scopes.h

Index: src/scopes.h
diff --git a/src/scopes.h b/src/scopes.h
index d4e8e2bd911b1ba1fef3e794db901ee50749b2f7..3f0f7564d184ad50292f27fb1d09865dea83f0d9 100644
--- a/src/scopes.h
+++ b/src/scopes.h
@@ -251,8 +251,13 @@ class Scope: public ZoneObject {
   int num_parameters() const { return params_.length(); }
 
   // The local variable 'arguments' if we need to allocate it; NULL otherwise.
+  // If arguments() exist, arguments_shadow() exists, too.
   Variable* arguments() const { return arguments_; }
 
+  // The '.arguments' shadow variable if we need to allocate it; NULL otherwise.
+  // If arguments_shadow() exist, arguments() exists, too.
+  Variable* arguments_shadow() const { return arguments_shadow_; }
+
   // Declarations list.
   ZoneList<Declaration*>* declarations() { return &decls_; }
 
@@ -350,6 +355,8 @@ class Scope: public ZoneObject {
   Variable* function_;
   // Convenience variable; function scopes only.
   Variable* arguments_;
+  // Convenience variable; function scopes only.
+  Variable* arguments_shadow_;
 
   // Illegal redeclaration.
   Expression* illegal_redecl_;