In Unicode, it is separately encoded as U+037E ; GREEK QUESTION MARK, but the similarity is so great that the code point is normalised to U+003B ; SEMICOLON, making the marks identical in practice.

Source: en.wikipedia.org/wiki/Question_mark

I’m still curious whether it would be accepted by the code interpreters / compilers of various languages. I’m not bold enough to assume they all normalise properly.