Fix crashes on QNX/x86

On x86 we assume that ebx holds the address of the global offset table for
position independent code. So before placing a run-time call we restore the
register from it's position we saved it on earlier on the stack. However after
commit d9f33ccdef985badc56fd8940373748626beffc7 the register wasn't saved on the
stack anymore in the prologue because we skipped because it's caller saved. So
when we seemingly reloaded ebx with the GOT from the stack, we loaded it from a location
we never saved it to. This patch makes sure to always save it on the stack so that
we can always restore it.

Change-Id: I8f6a8e38779151fff517f17220f29a7cb45ca89d
Task-number: QTBUG-43036
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>
Add string::arg method in installTranslatorFunctions

QJSEngine::installTranslatorFunctions install the translator functions
to any given JS object. However, the custom string::arg() method is only
added in qqmlbuiltinfunctions.cpp, making the use of qsTr() in other
pure-JS programs quite hard.

Task-number: QTBUG-43113
Change-Id: Ia9ed97a4c07a4d167c792f3ea13e4f6e96c97423
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Update plugins.qmltypes

Change-Id: I9b6c54b572d4653d609b154000e274b9e64d591f
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@theqtcompany.com>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
qttest: make findChild available only for QtTest 1.1

Change-Id: I4ceb1a969bd4296b82f899088b02b5e8cf100bcd
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
QQmlInspectorService: handle views only with supported plugins.

Task-number: QTBUG-43048
Change-Id: I5b32bd0a1e28fdf56b5346580daf21e7ec1b9f8c
Reviewed-by: Kevin Funk <kevin.funk@kdab.com>
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Merge remote-tracking branch 'origin/5.4.0' into 5.4

Change-Id: I5978bab8a4fde4c2ee33907fd81f49cb69e4fb26
Merge "Merge remote-tracking branch 'origin/5.4.0' into 5.4" into refs/staging/5.4
QML: fix warning in tests

Remove unused constant.

Change-Id: I3fb3512f7ea54102450eeeda1a56c73fe6b26025
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
QML: fix warning in tests

Remove unused function that wouldn't be emitted anyway.

Change-Id: I623d5d44bca9a1358cf9e66ff557992aba9ae451
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>