Remove ->last_unsafe from php_random_status

[TimWolla]

Whenever ->last_unsafe is set to true an exception has been thrown. Thus we
can replace the check for ->last_unsafe with a check for EG(exception)
which is a much more natural way to ommunicate an error up the chain.

[Danack]

@TimWolla I was about to ask you elsewhere, that having to remember to check the status->last_unsafe seemed prone to mistakes, and is hard to see where the exception is going to be thrown from. So in general I approve.

[Danack]

tbh, I don't fully understand this bit, but it looks like an exception has happened elsewhere, and the code is replacing that exception with a new one. Is it possible to set the previous exception, so that the info isn't lost?

And same comment for the other ones below.

[TimWolla]

Is it possible to set the previous exception, so that the info isn't lost?

zend_throw_exception is smart enough to do that automatically:

php-src/Zend/zend_exceptions.c

Line 182 in 9090e26

zend_object *previous = EG(exception);

This can be seen in action here:

php-src/ext/random/tests/03_randomizer/user_unsafe.phpt

Lines 135 to 143 in 9090e26

	Error: Failed to generate an acceptable random number in 50 attempts in %s:%d
	Stack trace:
	#0 %s(%d): Random\Randomizer->shuffleArray(Array)
	#1 {main}
	Next RuntimeException: Random number generation failed in %s:%d
	Stack trace:
	#0 %s(%d): Random\Randomizer->shuffleArray(Array)
	#1 {main}

I plan to fully remove the RuntimeException here in a future PR, though, so that the underlying error of the broken engine is directly exposed to the user. This PR focuses on the cleanup work to make that possible, one piece at a time.

[Danack]

Cool. TIL zend_throw_exception is smarter than me.

[TimWolla]

I was about to ask you elsewhere, that having to remember to check the status->last_unsafe seemed prone to mistakes

Indeed that's the motivation. And this PR is purely a cleanup without any functional change for the userland developer. #9071 already added exceptions in all places where ->last_unsafe was set, but I wanted to split this in a separate PR, as it's a different logical change.

[cmb69]

Looks reasonable to me. And since we haven't fixed the ABI yet, there is no reason to keep .last_unsafe.

[zeriyoshi]

LGTM. i was ignorant of the Execute Globals and exception handling.
Thanks!