Enable Zend Signals Handler By Default

Hey internal: There is also a problem we have been suffering from for a quite long time, that is signal raised at OOM/Timeout when execution is in a critical area will lead PHP crash or even more big troubles if it is in shared memory. You may still remember we disabled zend signal handlers before PHP-5.4 was released because it doesn't work well as mod_apache. which is described in #61083. Zend signal is a good way to fix the problem, thus I did some research then fixed zend signals(make it works with apache2handler), committed in https://github.com/php/php-src/commit/fd5a756ad44124ffa7e9a5810a31ff49e91708cf And no obviously performance affects in reallife app(benched with wordpress). Next, We may do some further optimizationes based on that. For now, I want to make zend signals handler enable by default (in configure) for PHP7, or maybe totally removed the --enable-zend-signals option? thus make zend_signal.c always be compiled and linked. Is there any concerns or objections on this? thanks -- Xinchen Hui @Laruence http://www.laruence.com/