Instead of force-loading the whole static library of the platform plugin
we tell the linker to look for the missing symbol qt_registerPlatformPlugin.
This symbol is provided by the same object file as the plugin's static
initializer, so the object file is included in the final binary and
the static initializer is run, resulting in the plugin registering with
Qt.
We could have marked the actual static initializer wrapper provided by
Q_IMPORT_PLUGIN(QIOSIntegrationPlugin) as undefined, but due to the C++
mangling this would look less intuitive on the linker command line than
the custom dummy function that we provide, which has C linkage.
Change-Id: I6805537e1f49260a41d48c555376964cb1fe75d8
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>