Strict mode arguments do not share binding with formal parameters.

src/ast-inl.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 84 matching lines @@
       body_id_(GetNextId()) {
 }
 
 
 ForInStatement::ForInStatement(ZoneStringList* labels)
     : IterationStatement(labels), each_(NULL), enumerable_(NULL),
       assignment_id_(GetNextId()) {
 }
 
 
+bool FunctionLiteral::strict_mode() const {
+  return scope()->is_strict_mode();
+}
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_AST_INL_H_