n. zend_hash_sort compare function signature change
o. cast_object() object handler is now required
p. ARG_COUNT() macro removed
+ r. GC_COLLECTABLE flag
2. Build system changes
a. Abstract
p. The ARG_COUNT() macro has been removed use ZEND_NUM_ARGS() instead.
+ r. GC_COLLECTABLE flag was inverted into GC_NOT_COLLECTABLE.
+ Assignments to GC_TYPE_INFO() maight need to be changed to properly
+ set the value of the GC_NOT_COLLECTABLE flag.
+
========================
2. Build system changes
========================