This is targeting 8.0.
`$arg` seems like a poor choice of a name,
especially if the function were to have arguments added.
In many cases, the php.net documentation already has $array for these functions.
E.g. https://www.php.net/manual/en/function.array-intersect.php
I'd assume that since named arguments was added to 8.0 near the feature freeze,
PHP's maintainers had planned to make the names consistent
and gradually use the same name for docs and implementation.
This test does not work on Windows, if the child process has OPcache
enabled via php.ini, since TEMP is not set in the environment, so
OPcache can't find the base address file, and terminates the childs.
To avoid this (and potentially some other issues regarding missing
environment variables, such as PATH), we force the child process to
ignore any ini files.
In this case the progarm will be executed directly, without a shell.
On Linux the arguments are passed directly to execvp and no escaping
is necessary. On Windows we construct a command string using escaping
with the default Windows command-line argument parsing method described
at https://docs.microsoft.com/en-us/cpp/cpp/parsing-cpp-command-line-arguments.
Apart from avoiding the issue of argument escaping, passing an array
and bypassing shell has the advantage of allowing proper signal
delivery to the opened process (rather than the shell).
