Change __defineGetter__ and __defineSetter__ to respect non-configurable....

test/mjsunit/accessors-on-global-object.js

 // Copyright 2010 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 10 matching lines @@
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Test that installing a getter on the global object instead of a
 // normal property works.
 
-var x = 0;
+x = 0;
 
 function getX() { return x; }
 
 for (var i = 0; i < 10; i++) {
   assertEquals(i < 5 ? 0 : 42, getX());
   if (i == 4) __defineGetter__("x", function() { return 42; });
 }
 
 
 // Test that installing a setter on the global object instead of a
 // normal property works.
 
-var y = 0;
+y = 0;
 var setter_y;
 
 function setY(value) { y = value; }
 
 for (var i = 0; i < 10; i++) {
   setY(i);
   assertEquals(i < 5 ? i : 2 * i, y);
   if (i == 4) {
     __defineSetter__("y", function(value) { setter_y = 2 * value; });
     __defineGetter__("y", function() { return setter_y; });
   }
 }
 
 
 // Test that replacing a getter with a normal property works as
 // expected.
 
 __defineGetter__("z", function() { return 42; });
 
 function getZ() { return z; }
 
 for (var i = 0; i < 10; i++) {
   assertEquals(i < 5 ? 42 : 0, getZ());
   if (i == 4) {
     delete z;
-    var z = 0;
+    z = 0;
   }
 }