Fix BcMath\Number unary plus/minus/bitwise-not

[mpesari]

Fixes phpstan/phpstan#13965

Returning ObjectType('BcMath\Number') from toNumber() fixed +$x and -$x but caused other tests to fail in these operations (https://github.com/phpstan/phpstan-src/blob/2.1.x/tests/PHPStan/Analyser/nsrt/bcmath-number.php)

• $a & $b
• $a | $b
• $a ^ $b
• $a << $b
• $a >> $b

This is fixed by checking for BcMath\Number early and returning ErrorType before calling toNumber() when handling those bitwise operations (getBitwiseAndTypeFromTypes() etc.)

I'm not sure if the *ERROR* -> *NEVER* changes in tests fix something or break something?

[VincentLanglet]

I'm not sure it's the right way to do it see
phpstan/phpstan#13965 (comment)

Given the fact we have a BcMathNumberOperatorTypeSpecifyingExtension I don't see why we would have the unary operator hardcoded.

So maybe the best way to do it the same way is to

• introduce UnaryOperatorTypeSpecifyingExtension
• implements it for BCMathNumber
• Introduce UnaryOperatorTypeSpecifyingExtensionRegistry and provider (or add a param to the construct of OperatorTypeSpecifyingExtensionRegistry)
• Use it in the InitializerExprTypeResolver the same way it's already used.

But I'd like the confirmation from someone else