Description:
------------
This (test script) code on PHP 7.1 throws the exception.
But on PHP 7.2 there is no such.


But if write at the end of the script:

unset($generator);

then PHP 7.2 throws the exception.

Sample: https://3v4l.org/JQEOj

Test script:
---------------
<?php
function shutdown(): \Generator
{
    try {
        yield;
    } finally {
        echo 'UNSET BEFORE yield', PHP_EOL;
        yield;
    }
}

$generator = shutdown();
$generator->rewind();

Expected result:
----------------
UNSET BEFORE yield

Fatal error: Uncaught Error: Cannot yield from finally in a force-closed generator...

Actual result:
--------------
UNSET BEFORE yield