Fix type for array_splice() argument $replacement

[spawnia]

Resolves phpstan/phpstan#6288

Thanks to @herndlm

[simPod]

I think we will need to also change

phpstan-src/src/Type/Php/ArraySpliceFunctionReturnTypeExtension.php

Line 21 in 4a25856

public function getTypeFromFunctionCall(

to merge the types.

But it might be tricky because of

Note: If replacement is not an array, it will be typecast to one (i.e. (array) $replacement). This may result in unexpected behavior when using an object or null replacement.

[herndlm]

I think we will need to also change

phpstan-src/src/Type/Php/ArraySpliceFunctionReturnTypeExtension.php

Line 21 in 4a25856

public function getTypeFromFunctionCall(

to merge the types.

I'm not sure if this is related to this PR. At least it reads and looks like it already ignores $replacement completely right now, which is not really correct yes, see https://phpstan.org/r/347cf306-c06c-462b-9daf-af41b2380da7. So it could be improved, but maybe in a follow-up?

Well, let's see what Ondrej says :)

[ondrejmirtes]

Thank you!

Anyone, feel free to send an update to the array_splice dynamic return type extension so that it reads the replacement argument :)