Make functions on the built-in object non-writable.

src/full-codegen.cc

 // Copyright 2011 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 566 matching lines @@
         }
       }
     }
     // Invoke the platform-dependent code generator to do the actual
     // declaration the global variables and functions.
     DeclareGlobals(array);
   }
 }
 
 
+int FullCodeGenerator::DeclareGlobalsFlags() {
+  int flags = 0;
+  if (is_eval()) flags |= kDeclareGlobalsEvalFlag;
+  if (is_strict_mode()) flags |= kDeclareGlobalsStrictModeFlag;
+  if (is_native()) flags |= kDeclareGlobalsNativeFlag;
+  return flags;
+}
+
+
 void FullCodeGenerator::SetFunctionPosition(FunctionLiteral* fun) {
   CodeGenerator::RecordPositions(masm_, fun->start_position());
 }
 
 
 void FullCodeGenerator::SetReturnPosition(FunctionLiteral* fun) {
   CodeGenerator::RecordPositions(masm_, fun->end_position() - 1);
 }
 
 
@@ skipping 786 matching lines @@
   }
 
   return false;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal