From ES 6 the ToPropertyKey operation is used to convert elements to a valid property key.
This "new" method uses the ToPrimitive operation which can call the `@@ToPrimitive`
well-known symbol to convert the given element to a key.
JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.usz@partner.samsung.com
Péter Gál