Merge branch '3.4' into 4.4

* 3.4:
  Disable the PhpUnit bridge when testing it
  [PropertyInfo] Support for the mixed type.
  [Form] Add Bosnian (bs) validators translation
  [Form] Add missing Serbian (latn & cyrl) validators translation
  [Form] [Validator] added pt_BR translations
  Estonian update
  [PhpUnitBridge] fix running parallel tests with phpunit 9
  [VarDumper] fix truncating big arrays

Author: nicolas-grekas

Cloner/VarCloner.php

@@ -240,7 +240,7 @@ protected function doClone($var)
                         $stub->position = $len++;
                     } elseif ($pos < $maxItems) {
                         if ($maxItems < $pos += \count($a)) {
-                            $a = \array_slice($a, 0, $maxItems - $pos);
+                            $a = \array_slice($a, 0, $maxItems - $pos, true);
                             if ($stub->cut >= 0) {
                                 $stub->cut += $pos - $maxItems;
                             }

Tests/Cloner/VarClonerTest.php

@@ -170,7 +170,7 @@ public function testLimits()
                     'Level 3 Item 3',
                 ],
                 [
-                    'Level 3 Item 4',
+                    999 => 'Level 3 Item 4',
                     'Level 3 Item 5',
                     'Level 3 Item 6',
                 ],
@@ -250,7 +250,7 @@ public function testLimits()
                     [1] => Array
                         (
                             [0] => 2
-                            [2] => 7
+                            [1] => 7
                         )
 
                     [2] => Array
@@ -307,7 +307,7 @@ public function testLimits()
 
             [7] => Array
                 (
-                    [0] => Level 3 Item 4
+                    [999] => Level 3 Item 4
                 )
 
         )