[php-src] Issue #11176: Embed SAPI (PHP_EMBED_START_BLOCK/PHP_EMBED_END_BLOCK) memory leak(?)

Issue: https://github.com/php/php-src/issues/11176 Author: jansssson ### Description I'm assuming it should be possible to run multiple (independent) embedded blocks, one after the other - I can't find information saying otherwise. My use case is somewhat advanced, but the repro is really simple. I cut out code until there was almost nothing left, and basically running multiple PHP_EMBED_START_BLOCK/PHP_EMBED_END_BLOCK result in an ever increasing memory consumption, which I guess is a leak of some kind. In my real use case, at the rate I'm executing embedded blocks, I see a steady linear increase in RSS of ~200MB/h, with the repro below it's ~1GB/h. Same result in PHP 8.2.4 and PHP 7.4.33. I've tried various properties/functions of the sapi_module_struct, it doesn't seem to make a difference, but for reference I have custom callbacks for the following methods: * php_embed_module.ub_write * php_embed_module.log_message * php_embed_module.sapi_error * zend_error_cb In essence, the PHP_EMBED_START_BLOCK/PHP_EMBED_END_BLOCK seem to be the culprit. The following code: ```#include "php_embed.h" int main() { while (1) { for(int i = 0; i < 1000; ++i) { PHP_EMBED_START_BLOCK(0, NULL) //zend_eval_string("echo phpinfo();", NULL, ""); PHP_EMBED_END_BLOCK() } //Check/print memory consumption } } ``` ``./test > /dev/null`` Resulted in this output: An increase of ~1GB RAM / hour in memory consumption But I expected this output instead: A somewhat steady memory consumption ### PHP Version PHP 8.2.4 ### Operating System _No response_