V4: fix register usage on ARM.

JSC was using r3 as the address scratch register, which collides with
the 4th parameter in a function call. This sometimes shows up when
generateFunctionCall needs to do a calulated jump.

Also fix the usage of r11, which seems to be the fp on some platforms.

Change-Id: Ib2ea64b9342e5aa631db6a7641747f899b2fbd89
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Refine fix for dynamic properties on QObjects wrapped in JavaScript

This is an ammendment to commit 60730cbb5e5475b5db6a15641211aa6958a93197
to further restrict the ability to set dynamic properties on JS wrapped
QObjects only on those that are associated with a qml context. Only one
such association comes with the static property lookup rules of QML and
therefore only those should be prohibited from dynamic properties.

The previous implementation on using the "compiledData" field to detect QML
association or not is not strong and reliable enough.

Change-Id: I10c0e6e58a2727c01a6cb56fdf912bf250333e1f
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>