https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109936
--- Comment #10 from Andreas Schwab <sch...@linux-m68k.org> ---
> The standard says "Each preprocessing token that is converted to a token
> (5.6) shall have the lexical form of a keyword, an identifier, a literal, or
> an operator or punctuator."
The argument of the macros is not converted to a token, but discarded in phase
4.
> ≠ cannot be used in an identifier, and it's none of the other forms either.
It is a valid preprocessing token ("non-whitespace character that cannot be one
of the above").
