language-specs: move constexpr from C++ to C
constexpr
is part of C23 and already supported by GCC 13.
https://en.cppreference.com/w/c/keyword
https://en.wikipedia.org/wiki/C23_(C_standard_revision)
constexpr
is part of C23 and already supported by GCC 13.
https://en.cppreference.com/w/c/keyword
https://en.wikipedia.org/wiki/C23_(C_standard_revision)