Merge branch '5.1' into 5.2

* 5.1:
  Dont allow unserializing classes with a destructor
  Dont allow unserializing classes with a destructor - 4.4
  [Cache] fix possible collision when writing tmp file in filesystem adapter
  a colon followed by spaces exclusively separates mapping keys and values
  Contracts: Remove ellipsis
  fix handling float-like key attribute values
  Fix missing BCC recipients in SES bridge
  Dont allow unserializing classes with a destructor - 5.1

Author: nicolas-grekas

Loader/Configurator/AbstractConfigurator.php

@@ -40,6 +40,16 @@ public function __call(string $method, array $args)
         throw new \BadMethodCallException(sprintf('Call to undefined method "%s::%s()".', static::class, $method));
     }
 
+    public function __sleep()
+    {
+        throw new \BadMethodCallException('Cannot serialize '.__CLASS__);
+    }
+
+    public function __wakeup()
+    {
+        throw new \BadMethodCallException('Cannot unserialize '.__CLASS__);
+    }
+
     /**
      * Checks that a value is valid, optionally replacing Definition and Reference configurators by their configure value.
      *