Fix delete someArray[index]
Fix delete someArray[index]

The current implementation resized the array, where as we should be
poking a whole into the array. With this patch that's done using
an explicit undefined value. In the future I guess the array will
support sparse segments.

Fixes currently failing tests:
 ch11/11.4/11.4.1/11.4.1-4.a-14 in non-strict mode
 ch15/15.4/15.4.4/15.4.4.18/15.4.4.18-7-2 in non-strict mode
 ch15/15.4/15.4.4/15.4.4.21/15.4.4.21-9-3 in non-strict mode

Change-Id: Idb0a230e38af3ce1f8f80f71257d472434154f95
Reviewed-by: Lars Knoll <a812617a4072dcbeb80684eca0f369f0083af109@digia.com>

matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,qmlc/qtdeclarative