Merge branch 'PHP-5.6'

* PHP-5.6:
  Fixed #67985 - Incorrect last used array index copied to new array after unset

Conflicts:
	Zend/zend_variables.c

Zend/tests/bug67985.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Bug #67985 - Last used array index not copied to new array at assignment
+--FILE--
+<?php
+
+$a = ['zero', 'one', 'two'];
+unset($a[2]);
+$b = $a;
+$a[] = 'three';
+$b[] = 'three';
+
+var_dump($a === $b);
+
+?>
+--EXPECT--
+bool(true)