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

src/macros.py

Index: src/macros.py
diff --git a/src/macros.py b/src/macros.py
index 5ba7ac3afa0307ed04ade9e7a9da043343c205d6..97c8c372d79cbe815273a48725f92923f65d7717 100644
--- a/src/macros.py
+++ b/src/macros.py
@@ -179,3 +179,17 @@ const SETTER_INDEX = 3;
 const WRITABLE_INDEX = 4;
 const ENUMERABLE_INDEX = 5;
 const CONFIGURABLE_INDEX = 6;
+
+# For messages.js
+# Matches Script::Type from objects.h
+const TYPE_NATIVE = 0;
+const TYPE_EXTENSION = 1;
+const TYPE_NORMAL = 2;
+
+# Matches Script::CompilationType from objects.h
+const COMPILATION_TYPE_HOST = 0;
+const COMPILATION_TYPE_EVAL = 1;
+const COMPILATION_TYPE_JSON = 2;
+
+# Matches Messages::kNoLineNumberInfo from v8.h
+const kNoLineNumberInfo = 0;