Request to add support for `Trait` in the extension layer

[matyhtf]

Description

Request to add a new ZendAPI: zend_class_use_traits that will allow internals classes in the extension to use Traits.

static zend_class_entry *register_class_TestClass(zend_class_entry *class_entry_TestClassInterface) {
	zend_class_entry ce, *class_entry;

	INIT_CLASS_ENTRY(ce, "TestClass", class_TestClass_methods);
	class_entry = zend_register_internal_class_ex(&ce, NULL);

	zend_class_use_traits(class_entry, 2, class_entry_TraitA, class_entry_TraitB);
}

[iluuu1994]

In that case, we should probably add support through stubs, i.e.:

trait T {
    public function foo() {}
}
class C {
    use T;
}