Merge branch '3.4' into 4.3

* 3.4:
  use utf8mb4_bin to align code with documentation
  [VarDumper] ignore failing __debugInfo()

Author: nicolas-grekas

Caster/Caster.php

@@ -48,6 +48,15 @@ class Caster
      */
     public static function castObject($obj, $class, $hasDebugInfo = false)
     {
+        if ($hasDebugInfo) {
+            try {
+                $debugInfo = $obj->__debugInfo();
+            } catch (\Exception $e) {
+                // ignore failing __debugInfo()
+                $hasDebugInfo = false;
+            }
+        }
+
         $a = $obj instanceof \Closure ? [] : (array) $obj;
 
         if ($obj instanceof \__PHP_Incomplete_Class) {
@@ -83,7 +92,7 @@ public static function castObject($obj, $class, $hasDebugInfo = false)
             }
         }
 
-        if ($hasDebugInfo && \is_array($debugInfo = $obj->__debugInfo())) {
+        if ($hasDebugInfo && \is_array($debugInfo)) {
             foreach ($debugInfo as $k => $v) {
                 if (!isset($k[0]) || "\0" !== $k[0]) {
                     $k = self::PREFIX_VIRTUAL.$k;