Remove some unnecessary binding initialization checks.

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 531 matching lines @@
                    // variable
 
   INTERNAL,        // like VAR, but not user-visible (may or may not
                    // be in a context)
 
   TEMPORARY        // temporary variables (not user-visible), never
                    // in a context
 };
 
 
+// ES6 Draft Rev3 10.2 specifies declarative environment records with mutable
+// and immutable bindings that can be in two states: initialized and
+// uninitialized. In ES5 only immutable bindings have these two states. When
+// accessing a binding, it needs to be checked for initialization. However in
+// the following cases the binding is initialized immediately after creation
+// so the initialization check can always be skipped:
+// 1. Var declared local variables.
+//      var foo;
+// 2. A local variable introduced by a function declaration.
+//      function foo() {}
+// 3. Parameters
+//      function x(foo) {}
+// 4. Catch bound variables.
+//      try {} catch (foo) {}
+// 6. Function variables of named function expressions.
+//      var x = function foo() {}
+// 7. Implicit binding of 'this'.
+// 8. Implicit binding of 'arguments' in functions.
+//
+// ES5 specified object environment records which are introduced by ES elements
+// such as Program and WithStatement that associate identifier bindings with the
+// properties of some object. In the specification only mutable bindings exists

[Jakob Kummerow, 2011/10/31 12:44:34]

nit: s/exists/exist/

[Steven, 2011/10/31 14:28:29]

Done.

+// (which may be non-writable) and have no distinct initialization step. However
+// V8 allows const declarations in global code with distinct creation and
+// initialization steps which are represented by non-writable properties in the
+// global object. As a result also these bindings need to be checked for
+// initialization.
+//
+// The following enum specifies a flag that indicates if the binding needs a
+// distinct initialization step (NEEDS_INITIALIZATION) or if the binding is
+// immediately initialized upon creation (CREATED_INITIALIZED).
+enum InitializationFlag {
+  NEEDS_INITIALIZATION,
+  CREATED_INITIALIZED
+};
+
+
 enum ClearExceptionFlag {
   KEEP_EXCEPTION,
   CLEAR_EXCEPTION
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_V8GLOBALS_H_