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

src/v8globals.h

 // 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 464 matching lines @@
                   CMOV = 15,   // x86
                   RDTSC = 4,   // x86
                   CPUID = 10,  // x86
                   VFP3 = 1,    // ARM
                   ARMv7 = 2,   // ARM
                   SAHF = 0,    // x86
                   FPU = 1};    // MIPS
 
 // The Strict Mode (ECMA-262 5th edition, 4.2.2).
 enum StrictModeFlag {
-  kNonStrictMode,
-  kStrictMode,
+  kNonStrictMode = 0,

[Kevin Millikin (Chromium), 2011/09/01 07:58:24]

I couldn't find a site where we relied on a specific values for kNonStrictMode
or kStrictMode, so I'd rather not make this change.

It suggests the reader here that we already *do* rely on a specific value and so
encourages him to make use of that fact.  There doesn't seem a good reason to
introduce that dependency.

[Lasse Reichstein, 2011/09/01 09:26:58]

Good catch. It's an artifact of a preliminary change that didn't make it.

+  kStrictMode = 1,
   // This value is never used, but is needed to prevent GCC 4.5 from failing
   // to compile when we assert that a flag is either kNonStrictMode or
   // kStrictMode.
   kInvalidStrictFlag
 };
 
 
 // Used to specify if a macro instruction must perform a smi check on tagged
 // values.
 enum SmiCheckType {
@@ skipping 15 matching lines @@
 static const uint32_t kNaNOrInfinityLowerBoundUpper32 = 0x7FF00000;
 
 const uint64_t kHoleNanInt64 =
     (static_cast<uint64_t>(kHoleNanUpper32) << 32) | kHoleNanLower32;
 const uint64_t kLastNonNaNInt64 =
     (static_cast<uint64_t>(kNaNOrInfinityLowerBoundUpper32) << 32);
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8GLOBALS_H_