The flags asOBJ_APP_CLASS_ALLINTS/FLOATS are used to tell AngelScript what the type of content the object has, so AngelScript can decide how the object should be passed to registered functions in native calling conventions. The only ABI so far that needs these flags is the AMD/Intel 64bit ABI that the g++ compiler uses. This specific ABI can decide to put the object in the CPU float registers or general registers depending on the type of the members of the class.
On any other platform or compiler the flags will have no effect.
The documentation that describes when/how to use these flags is here: