Update C++ standard list of --std option in manpage

[syohex]

The manpage only lists up to C++11 and it says C++11 is default. It is out-of-dated.

[firewave]

This is probably not the one things which is out-of-sync. I filed https://trac.cppcheck.net/ticket/12035 about finding an approach so we only need to modify a single location.

[chrchr-github]

We even (pretend aspire to) support C++23 (which also is the default) in our code.

[firewave]

We even (pretend aspire to) support C++23 (which also is the default) in our code.

Well, there is preliminary support in terms of keywords and the standard define. It is mostly important for the -std= compiler option we consume from projects. That is done via simplecpp though. That enables certain code for the analysis even if we do not support all the features.

That will actually become somewhat obsolete when we can deduce that directly from the compiler - but we are already well off the reservation, so let's get back on topic.

@syohex What name should we credit you with for your contribution?

[syohex]

@syohex What name should we credit you with for your contribution?

Shohei Yoshida, please.

[firewave]

Shohei Yoshida, please.

@danmar