[GIT-PULLS] [php-src] PR #23126: Fix GH-23115: stack overflow in compact() with deep arrays

Pull Request: https://github.com/php/php-src/pull/23126
Author: lazerg

php_compact_var() recurses once per nesting level with no stack check, so passing a deeply nested array to compact() exhausts the native stack and the process dies with a segfault.

This adds the same stack limit check ext/standard already uses in var.c and http.c, so the call throws an Error instead of crashing.

Fixes #23115.