Merge branch 'PHP-7.0' into PHP-7.1

diff --cc NEWS
index ec64fc53da39d2bd2e285d8228b7c3df750d468d,36b01a3453398f9331477d3ad3fc25b07fbba41d..9743a3218838848d9d43c7916c6adeeffe244e09
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -31,11 -53,10 +31,14 @@@ PH
    . Fixed bug #65732 (grapheme_*() is not Unicode compliant on CR LF
      sequence). (cmb)
  
 -- OCI8
 -  . Fixed invalid handle error with Implicit Result Sets. (Chris Jones)
 -  . Fixed bug #72524 (Binding null values triggers ORA-24816 error). (Chris Jones)
 +- JSON:
 +  . Implemented earlier return when json_encode fails, fixes bugs #68992
 +    (Stacking exceptions thrown by JsonSerializable) and #70275 (On recursion
 +    error, json_encode can eat up all system memory). (Jakub Zelenka)
 +
++- mbstring:
++  . Fixed bug #66797 (mb_substr only takes 32-bit signed integer). (cmb)
+ 
  - Opcache:
    . Fixed bug #72949 (Typo in opcache error message). (cmb)
  

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