Remove two reinterpret_casts in Object

Change-Id: I921cd8129acb47cffd58be9551a6925c4f296d41
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Move the indexing methods from SimpleArrayData to Heap::SimpleArrayData

Change-Id: I7d126999fb813bd9c0f224f7229d66854079f793
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reduce usage of Object::arrayData()

This will simplify porting over to returning Heap::ArrayData
from the method (as required for the new GC).

Change-Id: I5fb9ca7dfeab1aa63cc17c8948ef0966716f1bcb
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Operate directly on Heap::ArrayData where possible

Change-Id: I87dfb3e9a07673b5c405619eab8b6ee292d5c097
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>