Merge branch 'PHP-7.0' into PHP-7.1

diff --cc NEWS
index c18f87f7d708103815cc67f6d01a74ad05916ceb,4c21c43677b3b665f95b769944ed8a09029854dc..ec64fc53da39d2bd2e285d8228b7c3df750d468d
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -53,10 -78,13 +53,12 @@@ PH
  
  - SimpleXML:
    . Fixed bug #72971 (SimpleXML isset/unset do not respect namespace). (Nikita)
+   . Fixed bug #72957 (Null coalescing operator doesn't behave as expected with
+     SimpleXMLElement). (Nikita)
  
  - Standard:
 -  . Fixed bug #55451 (substr_compare NULL length interpreted as 0). (Lauri
 -    Kenttä)
 -  . Fixed bug #72278 (getimagesize returning FALSE on valid jpg). (cmb)
 +  . Fixed bug #72920 (Accessing a private constant using constant() creates
 +    an exception AND warning). (Laruence)
    . Fixed bug #65550 (get_browser() incorrectly parses entries with "+" sign).
      (cmb)
    . Fixed bug #71882 (Negative ftruncate() on php://memory exhausts memory).

diff --cc ext/simplexml/simplexml.c
Simple merge