[php-src] PR #23291: Share the method's runtime cache with fake closures of the same scope

Pull Request: https://github.com/php/php-src/pull/23291 Author: staabm Creating a fake closure (Closure::fromCallable(), first-class callable syntax, ReflectionMethod::getClosure()) over a method whose runtime cache was not yet initialized allocated a cold per-closure heap cache on every creation. Initialize the method's own shared cache instead - exactly what the first real call would do - so repeated closure creations reuse one warm cache. Trampolines and heap-cache functions keep the per-closure path. --- after this PR ``` ➜ php-src git:(closure) ✗ hyperfine 'sapi/cli/php -n -d opcache.enable_cli=0 closure_from_callable_runtime_cache_bench.php' Benchmark 1: sapi/cli/php -n -d opcache.enable_cli=0 closure_from_callable_runtime_cache_bench.php Time (mean ± σ): 136.5 ms ± 1.4 ms [User: 132.8 ms, System: 2.3 ms] Range (min … max): 133.4 ms … 138.7 ms 21 runs ``` before this PR ``` ➜ php-src git:(closure) ✗ hyperfine 'sapi/cli/php_old -n -d opcache.enable_cli=0 closure_from_callable_runtime_cache_bench.php' Benchmark 1: sapi/cli/php_old -n -d opcache.enable_cli=0 closure_from_callable_runtime_cache_bench.php Time (mean ± σ): 150.6 ms ± 1.3 ms [User: 147.2 ms, System: 2.3 ms] Range (min … max): 148.3 ms … 152.9 ms 19 runs ``` benchmark closure_from_callable_runtime_cache_bench.php: https://gist.github.com/staabm/20c082674ed880c8fc097b4775f2d7a7