Support eq and notEq

[herndlm]

I don't think they add much value, but why not.
Maybe that loosely type narrowing helps prevent errors somewhere :)

[ondrejmirtes]

Please add some tests that might trick the current implementation and the problems we're trying to solve, like $a == $a (always true) and also createStdClass() == createStdClass() (not always true). Thanks 😊

[herndlm]

added some more tests, but I'm not entirely sure what I'm finding here and what is expected and what not. I think this needs a double-check from you :)
== is quite tricky for me compared to === where things are pretty clear

And while looking at https://www.php.net/manual/en/language.operators.comparison.php I think we could come up with more weird constant comparisons where type-juggling is involved, like 100 == "1e2" which always evaluates to equal, but I'm not sure if this is still relevant here.

[herndlm]

Btw. I'm going to add more impossible-check tests for === in a similar fashion in another PR

[ondrejmirtes]

There's still one failure and I have no idea why.

[ondrejmirtes]

Alright ,the error "+54: Call to static method Webmozart\Assert\Assert::eq() with stdClass and mixed will always evaluate to true." should not be reported, but the root issue here is that PHPStan actually doesn't see the function declaration, because it's not loaded.

Please rewrite these tests to use classes+methods, it's more reliable (and you don't have to require_once those files).

[ondrejmirtes]

Thank you!