Merge branch '3.4' into 4.3

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

Session/Storage/Handler/PdoSessionHandler.php

@@ -218,7 +218,7 @@ public function createTable()
                 // - trailing space removal
                 // - case-insensitivity
                 // - language processing like é == e
-                $sql = "CREATE TABLE $this->table ($this->idCol VARBINARY(128) NOT NULL PRIMARY KEY, $this->dataCol BLOB NOT NULL, $this->lifetimeCol INTEGER UNSIGNED NOT NULL, $this->timeCol INTEGER UNSIGNED NOT NULL) COLLATE utf8_bin, ENGINE = InnoDB";
+                $sql = "CREATE TABLE $this->table ($this->idCol VARBINARY(128) NOT NULL PRIMARY KEY, $this->dataCol BLOB NOT NULL, $this->lifetimeCol INTEGER UNSIGNED NOT NULL, $this->timeCol INTEGER UNSIGNED NOT NULL) COLLATE utf8mb4_bin, ENGINE = InnoDB";
                 break;
             case 'sqlite':
                 $sql = "CREATE TABLE $this->table ($this->idCol TEXT NOT NULL PRIMARY KEY, $this->dataCol BLOB NOT NULL, $this->lifetimeCol INTEGER NOT NULL, $this->timeCol INTEGER NOT NULL)";