Add array_str_contains() function to standard library

[sepehrphpr]

Summary

This PR introduces the array_str_contains(array $haystack, string $needle): array function to the standard library for PHP 8.7.

Motivation

Filtering arrays based on substring matching is a very common task in PHP applications. Currently, developers often use:

array_filter($array, fn($item) => is_string($item) && str_contains($item, $needle));
Providing a dedicated internal implementation in C brings significant performance improvements, reduces userland boilerplate, and offers an intuitive API consistent with str_contains().
Behavior & Details

    Filtering & Key Preservation: Returns an array containing only the elements that contain $needle, preserving their original keys (both numeric and string keys).
    Type Handling: Safely ignores non-string values within the array without throwing notices/warnings.
    Empty Needle: If $needle is an empty string "", it matches all string elements (consistent with str_contains()).
    Binary & UTF-8 Safe: Built on top of php_memnstr(), ensuring fast and safe matching for UTF-8 / multi-byte characters and binary strings.
    Memory & Refcount Safe: Properly handles zval dereferencing and reference counting without leaks.

Tests

Added comprehensive test suite covering basic matching, numeric/string key preservation, non-string filtering, empty needle, and UTF-8 multi-byte strings in ext/standard/tests/array/array_str_contains..phpt

[devnexen]

Hi @sepehrphpr just personal take, it is a hard sell. Some people will likely question some design choices (e.g. it drops everything silently as opposed to str_contains ... what about case insensitiveness ? ...). Therefore I invite you to discuss its merit(s) on the internal mailing list at least.

[youkidearitai]

CI is red, But it is not CI's timeout. Test case is wrong.
Please build and test on your PC before push.

[aoto-tech]

I think this needs more design discussion before the implementation can be reviewed meaningfully.

This introduces a new standard library function, but the semantics are not obvious to me. In particular, silently dropping non-string values makes this behave differently from applying str_contains() in userland, and the expected behavior around case sensitivity, coercion, and mixed arrays probably needs to be agreed first.