Merge branch 'PHP-7.1'

* PHP-7.1:
  Update NEWS
  Fix memory leak(null coalescing operator with Spl hash)

ext/spl/tests/observer_010.phpt

@@ -0,0 +1,15 @@
+--TEST--
+SPL: SplObjectStorage null coalescing operator memory leak
+--FILE--
+<?php
+// In maintainer zts mode, this should no longer
+// detect memory leaks for the objects
+$a = new stdClass();
+$b = new stdClass();
+$map = new SplObjectStorage();
+$map[$a] = 'foo';
+var_dump($map[$b] ?? null);
+var_dump($map[$a] ?? null);
+--EXPECTF--
+NULL
+string(3) "foo"