Don't mutate $limit argument from 0 to -1 and from -1 to 0 in preg_split function

[sidz]

This PR stops mutate $limit argument from 0 to -1 and from -1 to 0 in preg_split function.

Requested in #1345

[vjik]

It is wrong to completely deny mutations.
There must be mutations more 0 and less -1.

[sidz]

@vjik added more tests to show that it works.

But found an issue with Decrement mutator when
preg_split('//', 'string', 1);

Because of:

infection/src/Mutator/Number/DecrementInteger.php

Lines 82 to 84 in 5682c2e

	if (!$node instanceof Node\Scalar\LNumber || $node->value === 1) {
	return false;
	}

and similar with Increment mutator when:
preg_split('//', 'string', 0);

Because of:

infection/src/Mutator/Number/IncrementInteger.php

Lines 71 to 73 in f8cf148

	return $node instanceof Node\Scalar\LNumber
	&& $node->value !== 0
	&& !$this->isPartOfSizeComparison($node);

[vjik]

See #1350

IncrementInteger work fine without fixes. Problems with DecrementInteger and OneZeroInteger.

[sidz]

@vjik IncrementInteger doesn't work - https://infection-php.dev/r/1lr (proof)

[vjik]

@vjik IncrementInteger doesn't work - https://infection-php.dev/r/1lr (proof)

IncrementInteger don't work for preg_split('//', 'string', -1); => preg_split('//', 'string', 0); — that is right.
In other cases IncrementInteger it works — thas is also right.

[maks-rafalko]

👌

[sidz]

@vjik I suppose all possible cases were covered. PR is ready for review.

IncrementInteger don't work for preg_split('//', 'string', -1); => preg_split('//', 'string', 0); — that is right.

It didn't work right as mutators had an issue with negative values. This behavior was fixed in #1351. So current master will mutate values from -1 to 0.

[sanmai]

Tests are sensible.

[maks-rafalko]

Thank you @sidz 👍