Merge branch '2.7' into 2.8

* 2.7:
  don't keep internal state between parser runs
  Add \Traversable typehint to phpdoc
  [ExpressionLanguage] Avoid dependency on ctype
  [Debug] Fix php notice

Author: xabbuh

Lexer.php

@@ -45,7 +45,7 @@ public function tokenize($expression)
             if (preg_match('/[0-9]+(?:\.[0-9]+)?/A', $expression, $match, null, $cursor)) {
                 // numbers
                 $number = (float) $match[0];  // floats
-                if (ctype_digit($match[0]) && $number <= PHP_INT_MAX) {
+                if (preg_match('/^[0-9]+$/', $match[0]) && $number <= PHP_INT_MAX) {
                     $number = (int) $match[0]; // integers lower than the maximum
                 }
                 $tokens[] = new Token(Token::NUMBER_TYPE, $number, $cursor + 1);