[Discussion] Add date_test_set_now() function

Hi, Internals. I've been absent for a long time due to poor health. I'm finally back. I maintain a legacy application written in PHP, and occasionally need to fake the current time for testing purposes. However, PHP doesn't provide a standard way to fake the current time, so I've been changing the OS's current time to do this, which is quite painful. This can be avoided by using third-party libraries (such as Carbon::setTestNow()). However, it's almost impossible to modify all parts of a legacy application that depend on the current time. Another option is to use libfaketime (https://github.com/wolfcw/libfaketime), but this is also quite painful to use. Since this was absolutely necessary for my work, I implemented this functionality as a PHP Extension. (Please ignore the dirty implementation related to PDO. I'm not planning to propose it this time.) https://github.com/colopl/php-colopl_timeshifter However, this Extension has some problems. The first is that there's no way to determine whether the format passed to the ext-date parser is relative or absolute time, resulting in a dirty hack using usleep. The second is that it depends on timelib, so it breaks when upstream changes related to timelib are made. So, how about adding a date_set_test_now(\DateInterval $shiftInterval) function to ext-date? This function would treat the current time as shifted by the passed DateInterval. Since it's implemented on the ext-date side, there's no need for dirty hacks using usleep. I'd like to hear your opinions. Thank you. Best Regards, Go Kudo