applicationName() default value broken on macOS

macOS with qtbase/dev, using ninja. QCoreApplication::applicationName() returns "${PRODUCT_NAME}" unless the application calls setApplicationName(). This is wrong and breaks the behavior promised in the docs: "If not set, the application name defaults to the executable name"
 
This can have more serious consequences on a number of things, for example consider QStandardPath::CacheLocation: it now returns "/Users/<user>/Library/Caches/${PRODUCT_NAME}" for any application that does not explicitly set a name.