Make stack property collected by captureStackTrace non-enumerable and -writable.

test/mjsunit/stack-traces.js

 // Copyright 2009 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 363 matching lines @@
 assertEquals("abc", error.stack);
 
 error = new Error();
 error.__defineGetter__("name", function() { delete error.stack; });
 assertEquals(undefined, error.stack);
 
 // Check that repeated trace collection does not crash.
 error = new Error();
 Error.captureStackTrace(error);
 
+// Check property descriptor.
+var o = {};
+Error.captureStackTrace(o);
+assertEquals([], Object.keys(o));
+var desc = Object.getOwnPropertyDescriptor(o, "stack");
+assertFalse(desc.writable);
+assertFalse(desc.enumerable);
+assertTrue(desc.configurable);
+
 // Check that exceptions thrown within prepareStackTrace throws an exception.
 Error.prepareStackTrace = function(e, frames) { throw 42; }
 
 var x = {}
 assertThrows(() => Error.captureStackTrace(x));