Merge branch 'PHP-7.3' into PHP-7.4

* PHP-7.3:
  Fix #75457: heap-use-after-free in php7.0.25

Author: smalyshev

ext/pcre/tests/bug75457.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Bug #75457 (heap-use-after-free in php7.0.25)
+--FILE--
+<?php
+$pattern = "/(((?(?C)0?=))(?!()0|.(?0)0)())/";
+var_dump(preg_match($pattern, "hello"));
+?>
+--EXPECTF--
+Warning: preg_match(): Compilation failed: assertion expected after (?( or (?(?C) at offset 4 in %sbug75457.php on line %d
+bool(false)