Android: Fix abi detection for 64bit devices

Change-Id: Idde12cd5bcd54d007245d3bdd93e8ab47d7f214b
Reviewed-by: Paul Olav Tvete <paul.tvete@theqtcompany.com>
Debugger: Centralize handling of optimized out values with GDB

There were a couple of situation where the is_optimized_out flag
was not used and later produced (caught) exceptions on access,
or where the still availably type was not shown.

Change-Id: I7ad5aa09a19357e50739d9fdf32f7423e30fe011
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>