Update NEWS/UPGRADING with info about incompat ctx

Author: cataphract

NEWS

@@ -6,6 +6,9 @@ PHP                                                                        NEWS
   . Improved IS_VAR operands fetching. (Laruence, Dmitry)
   . Implemented internal operator overloading
     (RFC: https://wiki.php.net/rfc/operator_overloading_gmp). (Nikita)
+  . Made calls from incompatible context issue an E_DEPRECATED warning instead
+    of E_STRICT (phase 1 of RFC: https://wiki.php.net/rfc/incompat_ctx).
+	(Gustavo)
 
 - Session:
   . Fixed Bug #65315 (session.hash_function silently fallback to default md5)

UPGRADING

@@ -35,6 +35,9 @@ PHP X.Y UPGRADE NOTES
 3. Deprecated Functionality
 ========================================
 
+- Incompatible context calls:
+  Instance calls from an incompatible context are now deprecated and issue
+  E_DEPRECATED instead of E_STRICT. See https://wiki.php.net/rfc/incompat_ctx
 
 ========================================
 4. Changed Functions