Improve non-array specification for recently cleaned-up array functions

[herndlm]

array_fill_keys: https://3v4l.org/8ik8V
array_flip: https://3v4l.org/jBASO
array_keys: https://3v4l.org/TYWrU
array_values: https://3v4l.org/89UDN

I was lazy with the pre PHP 8 checks and just wrapped them in conditionals like I did it with array_search. should the test files be split maybe to assert this for PHP < 8 as well? or not worth the hassle? hmm. we could maybe also move them all out to 2 test files only. e.g. non-array-array-functions.php and non-array-array-functions-php8.php or so

[phpstan-bot]

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[ondrejmirtes]

Awesome, thank you!

[herndlm]

are you fine with the tests like that or should I add more / split them so that we have more executing on PHP < 8 as well?

[ondrejmirtes]

The best would be (for each function):

• Have common file that's always tested on every PHP version for things that don't change
• Have a PHP 7 specific file
• Have a PHP 8 specific file