Merge branch 'PHP-7.3' into PHP-7.4

* PHP-7.3:
  Handle NULL caller_call_opline

diff --cc ext/opcache/Optimizer/dfa_pass.c
Simple merge

diff --cc ext/opcache/Optimizer/sccp.c
Simple merge

diff --cc ext/opcache/Optimizer/zend_call_graph.c
Simple merge

diff --cc ext/opcache/Optimizer/zend_inference.c
Simple merge