Fix tests on 32-bit

[herndlm]

I know this is kind of esoteric, but this was the only thing that prevented me to cleanly ran make with php 8.1 on my 32-bit raspberry pi:

$ uname -msr
Linux 5.10.90-1-rpi-legacy-ARCH armv7l

I had to add 1G of swap to make it run without freezing the system, but this would in general make the build green on 32-bit. No idea if it's really worth pursuing though, but good to know at least, that right now, even without this fix, phpstan runs still just fine on 32-bit :)

The reason is that this test defines a numeric in a string that is bigger than PHP_INT_MAX, casts it to int and then string again. and the int cast behaves different, depending on PHP_INT_SIZE. https://3v4l.org/enuv2

Only doing that because in #693 some 32/64-bit questions came up. The only important thing, I'd say, is to still support scanning code made for 32-bit, phpstan doesn't have to run on 32-bit. But right know it still could, so I'm just trying to find an answer to the question if we still should support running it on 32-bit :) And if yes - how to make sure it stays like that? If not - is it fine to just drop the runtime support then?

[ondrejmirtes]

Nice, thank you!