phpw_run() doesn't set `PG(during_request_startup) = 0`

[TimWolla]

Running the example on https://www.php.net/manual/en/function.exec.php results in:

Warning: PHP Request Startup: Unable to fork [whoami] in php-wasm run script on line 6
Returned with status -1 and output:
Array
(
)

It confusingly indicates a “PHP Request Startup” warning, instead of exec(). This is caused by PG(during_request_startup) == 1. php_execute_script() does this automatically:

https://github.com/php/php-src/blob/6e759e079f882fe54afa6da31f9cc86e9f680bf6/main/main.c#L2531

But for phpw_run() which uses zend_eval_string() this likely needs to happen manually.