This PR is created from #2290
The Github UI is stuck using that PR, so a new PR has been created.
https://a8c.slack.com/archives/C04BURZDHFH/p1753189537944499

Motivation for the change, related issues

Related to #2251

With this PR, we are adding support for OPCache by introducing a new WITH_OPCACHE argument, true by default.

Implementation details

The OPCache library is always compiled as a dynamic library. Once #2248 is merged, we can proceed to use the dynamic library generated instead of forcing a static compilation by patching ext/opcache/config.m4.

Caching mechanism

The OPCache .m4 file performs a series of tests.

In this PR, we force the Autoconf to recognize the mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0); emulated shared (anonymous) memory by renaming have_shm_mmap_anon (renamed to php_cv_shm_mmap_anon in PHP 8.4).

Additional

Starting with Python 3.12, distutils was removed from the standard library after being deprecated in Python 3.10. Here, we force the last version to ensure that node-gyp/gyp/gyp_main.py does not crash during compilation because it does not find the module.

Testing Instructions (or ideally a Blueprint)

First test

Open phpinfo.php and search for "Zend OPCache". It should be "Up and Running" and "OK" on startup

Second test

Try this blueprint (https://gist.github.com/zaerl/3e60bff32e1e915d5acc509bd50e9762). It will load WordPress +20 times so it will not open immediately.
"Cached" should be true, all the GET responses 200 OK. The opcache_enabled field will be false. It is a well-known PHP feature bug. Now open packages/php-wasm/universal/src/lib/php.ts and comment out these two lines:

// 'opcache.file_cache_only = 1',
// 'opcache.file_cache_consistency_checks = 1',

The same page will show more details and an hit rate ~75%. Now visit wp-admin, open some page. Go back to opcache.php, it should show ~90% or better.