Increase the reference count of object, and possibly remove the floating
reference, if object has a floating reference.
In other words, if the object is floating, then this call "assumes ownership"
of the floating reference, converting it to a normal reference by clearing
the floating flag while leaving the reference count unchanged. If the object
is not floating, then this call adds a new normal reference increasing the
reference count by one.
Increase the reference count of object, and possibly remove the floating reference, if object has a floating reference. In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.