Introduce PHP_INT_MAX_SAFE constant similar to JS's Number.MAX_SAFE_INTEGER constant

Hello internals, I'm mailing the list for the bike shed of the naming of a new constant I think we should introduce in PHP which I'm currently calling PHP_INT_MAX_SAFE.. The purpose of this integer is to indicate what is the maximal integer value that can be correctly represented by a float. On 32 bits this is equal to PHP_INT_MAX, but on 64 bits it is 9007199254740991 (which is 2^(53) – 1) as the mantissa of a floating point number is 52 bits. For more information, please see the MDN documentation about Number.MAX_SAFE_INTEGER. [1] The implementation is very simple and the PR is https://github.com/php/php-src/pull/19126 Best regards, Gina P. Banyard [1] https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER