Handle dynamic return types for bc math functions

[eigan]

Not sure if this should be split into multiple extensions, kept it at one because they all had very similar logic.

[eigan]

Well this got way more complicated than what I initially thought.. Might need some more tests too. Noticed that PHP doesnt always return the value as described in doc either.

[ondrejmirtes]

It's never easy :) Keep me posted, thanks. You can run the build locally to get faster feedback too - I'd run vendor/bin/phing cs, tests-fast, and phpstan.

[eigan]

I think im done with this now @ondrejmirtes. I have verified my assertions here https://3v4l.org/RWD9r. Some testcases fails, but they seem to be unrelated.

[ondrejmirtes]

It'd be nice if someone brought this PR over the finish line and verified that it also handles phpstan/phpstan#3551.

[eigan]

This PR is ready for another review @ondrejmirtes.

1) PHPStan tests fail. I thought PHPStan would understand the code written?

$secondArgumentIsConstant = $secondArgument instanceof ConstantScalarType;
$secondArgumentIsNumeric = $secondArgumentIsConstant && is_numeric($secondArgument->getValue());

Call to an undefined method PHPStan\Type\Type::getValue()

2) Tests fails on 7.4 and 8.0. Seems to be unrelated.

3) Code is a mess 😞

[eigan]

Rebased on master and refactored the code so the tests passes (mentioned why in last comment).

[ondrejmirtes]

Please rebase one more time and then I'll merge it, thank you.

[eigan]

✔️

[ondrejmirtes]

Thank you!