[php-src] Issue #15375: Generator with double enclosed `yield from` and `valid` call will skip items

Issue: https://github.com/php/php-src/issues/15375 Author: malofan ### Description The following code: ```php <?php function arrayProvider() { yield [ 'one', 'two', 'three', ]; yield [ 'four', 'five', 'six', ]; yield [ 'seven', 'eight', 'nine', ]; } function iterateValues(array $array) { foreach ($array as $value) { yield $value; } } function g1() { foreach (arrayProvider() as $array) { $iterator = iterateValues($array); if ($iterator?->valid()) { yield from $iterator; } } } function g2() { yield from g1(); } foreach (g2() as $s) { echo $s . PHP_EOL; } ``` Resulted in this output: ``` one two three five six eight nine ``` But I expected this output instead: ``` one two three four five six seven eight nine ``` https://3v4l.org/GdcNh So if we in g2 we'll try to yield from generator g1() AND in g1 we'll try to yield from generator iterateValues() BUT will call valid for it before then this valid call will move pointer to next element of generator. It replicates ONLY with yield from -> yield from combination AND valid call inside. Removing valid call or one yield from, as well as replacing yield from generator iterateValues() to foreach: yield will solve the problem. Also in test done by @lifinsky were found that following code in g1: ```php $iterator->next(); yield from $iterator; ``` Resulted in this output: ``` two three six nine ``` When expected: ``` two three five six eight nine ``` https://3v4l.org/Aq6NF So next call also jumps and results in missed values. ### PHP Version 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.29, 8.2.0 - 8.2.22, 8.3.0 - 8.3.10 ### Operating System _No response_