Merge branch 'PHP-8.0'

* PHP-8.0:
  Allow observer handlers disabling optimization in RETURN opcode handler, that may cause loss value of returned local variable.

diff --cc Zend/zend_compile.h
Simple merge

diff --cc Zend/zend_vm_def.h
Simple merge

diff --cc Zend/zend_vm_execute.h
Simple merge