Fix tst_qqmlcomponent::onDestructionLookup

Don't rely on the JIT generated code to immediately discard and ignore
the return value of createObject(). Instead move that call into another
function that, so that the return value of createObject() is guaranteed
to be invisible to the GC and thus collect the recently created object
as expected.

Change-Id: I08a0a35fc895482792deffbae7f7f6437727d871
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Fix qqmlmoduleplugin

Adjust the expected error message after commit 227f7ed60cfb34f7c3d91b27b07ddc5bbd1a2922

Change-Id: I328072dfb0151d6cd9b8452d8d3f9a306a132203
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Mark qqmlecmascript::hasOwnProperty as xfail

hasOwnProperty is not currently properly supported on dynamic objects that
re-implement get.

Change-Id: Ib6cfe13bbdbe4457adf05cd20e42d3a5e85ac318
Reviewed-by: Lars Knoll <lars.knoll@digia.com>