FPM: Freeing child allocated data

Description

FPM allocates some data during child initialization for keeping around some configuration options. This is done in following places:

• https://github.com/php/php-src/blob/15184435007ae13d31902be2613632b813b80b0f/sapi/fpm/fpm/fpm_log.c#L81 (this was reported in https://bugs.php.net/bug.php?id=75635 and it is the reason for creating this issue).
• https://github.com/php/php-src/blob/15184435007ae13d31902be2613632b813b80b0f/sapi/fpm/fpm/fpm_log.c#L91
• https://github.com/php/php-src/blob/15184435007ae13d31902be2613632b813b80b0f/sapi/fpm/fpm/fpm_status.c#L32
• https://github.com/php/php-src/blob/15184435007ae13d31902be2613632b813b80b0f/sapi/fpm/fpm/fpm_status.c#L40-L41
• https://github.com/php/php-src/blob/15184435007ae13d31902be2613632b813b80b0f/sapi/fpm/fpm/fpm_php.c#L219-L221 (this just takes ownership but means the same sort of leak effectively)

Those values are never freed. They are needed for the whole life of child so it is not a big issue as it gets released on process exit (that's why this is classified more as a feature and not a bug because there is no impact of this). However it is a good convention to free those values so some child destroy functions should be created for that purpose and called before exiting the child.

首先阅读 sapi/fpm/fpm/fpm_log.c、fpm_status.c 和 fpm_php.c 中的子进程初始化代码，然后跟踪子进程退出路径。为 issue 中列出的分配添加相应的子进程销毁处理，并在子进程退出前调用它。完成的标准是这些由子进程拥有的值会在关闭期间释放，而不是仅在进程退出时释放。