[php-src] Issue #9191: MT_RAND_PHP causes undefined behavior

Issue: https://github.com/php/php-src/issues/9191 Author: zeriyoshi ### Description The scaling algorithm used internally by MT_RAND_PHP causes undefined CPU-dependent behavior. This breaks compatibility of the MT random number sequences generated across platforms. (Its properties as a random number are already broken because it is improperly used.) The following code: ```php mt_srand(1234, MT_RAND_PHP); echo mt_rand(PHP_INT_MIN, PHP_INT_MAX) . PHP_EOL; ``` Resulted in this output: - i386: 0 - amd64: 0 - arm32v7: -1 - arm64v8: -1 - s390x: -1 Easily reproduced in QEMU's available Docker environment: ```shell $ docker run --rm -it i386/php:7.4-cli -r 'mt_srand(1234, MT_RAND_PHP); echo mt_rand(PHP_INT_MIN, PHP_INT_MAX) . PHP_EOL;' 0 $ docker run --rm -it amd64/php:7.4-cli -r 'mt_srand(1234, MT_RAND_PHP); echo mt_rand(PHP_INT_MIN, PHP_INT_MAX) . PHP_EOL;' 0 $ docker run --rm -it arm32v7/php:7.4-cli -r 'mt_srand(1234, MT_RAND_PHP); echo mt_rand(PHP_INT_MIN, PHP_INT_MAX) . PHP_EOL;' -1 $ docker run --rm -it arm64v8/php:7.4-cli -r 'mt_srand(1234, MT_RAND_PHP); echo mt_rand(PHP_INT_MIN, PHP_INT_MAX) . PHP_EOL;' -1 $ docker run --rm -it s390x/php:7.4-cli -r 'mt_srand(1234, MT_RAND_PHP); echo mt_rand(PHP_INT_MIN, PHP_INT_MAX) . PHP_EOL;' -1 ``` But I expected this output instead: This should probably be an error since it is beyond the range of getrandmax(), but should be unified to 0 or -1 for compatibility. ### PHP Version PHP 7.4.x (All supported version) ### Operating System Debian 11