Update return type for apcu_dec function

Author: LordSimal

resources/functionMap.php

@@ -138,7 +138,7 @@
 'apcu_cache_info' => ['__benevolent<array<string,mixed>|false>', 'limited='=>'bool'],
 'apcu_cas' => ['bool', 'key'=>'string', 'old'=>'int', 'new'=>'int'],
 'apcu_clear_cache' => ['bool'],
-'apcu_dec' => ['int', 'key'=>'string', 'step='=>'int', '&w_success='=>'bool', 'ttl='=>'int'],
+'apcu_dec' => ['false|int', 'key'=>'string', 'step='=>'int', '&w_success='=>'bool', 'ttl='=>'int'],
 'apcu_delete' => ['bool', 'key'=>'string|APCuIterator'],
 'apcu_delete\'1' => ['list<string>', 'key'=>'string[]'],
 'apcu_entry' => ['mixed', 'key'=>'string', 'generator'=>'callable', 'ttl='=>'int'],