Finally drop outdated misleading runtime.js comment.

src/runtime.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This files contains runtime support implemented in JavaScript.
 
 // CAUTION: Some of the functions specified in this file are called
 // directly from compiled code. These are the functions with names in
-// ALL CAPS. The compiled code passes the first argument in 'this' and
-// it does not push the function onto the stack. This means that you
-// cannot use contexts in all these functions.
+// ALL CAPS. The compiled code passes the first argument in 'this'.
 
 
 /* -----------------------------------
    - - -   C o m p a r i s o n   - - -
    -----------------------------------
 */
 
 // The following declarations are shared with other native JS files.
 // They are all declared at this one spot to avoid redeclaration errors.
 var $Object = global.Object;
@@ skipping 634 matching lines @@
   return i;
 }
 
 
 // NOTE: Setting the prototype for Array must take place as early as
 // possible due to code generation for array literals.  When
 // generating code for a array literal a boilerplate array is created
 // that is cloned when running the code.  It is essential that the
 // boilerplate gets the right prototype.
 %FunctionSetPrototype($Array, new $Array(0));