[new compiler] Fix test with aggressive gc

We need a scope object protector right after creating the JS wrapper,
which is right after creating the VME meta object.

Change-Id: I76668027486a44bab35a3193b4c1c6fbab5c3e0e
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
[new compiler] Cleanup object creator members

Collect variables shared across recursive instances in a SharedData
structure, get rid of some other members.

Change-Id: I8d52fbb34820ce17d754b91c3fdee9e534a95753
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
[new compiler] Match class and file name

QmlObjectCreator -> QQmlObjectCreator

Change-Id: I23da2d9c7fa0dcd760f5cc695c1759b44d1e72f0
Reviewed-by: Lars Knoll <lars.knoll@digia.com>