Commit a700e3b

#define @\defnlibxname{cpp_lib_constexpr_bitset}@ 202207L // also in \libheader{bitset}

#define @\defnlibxname{cpp_lib_constexpr_charconv}@ 202207L // also in \libheader{charconv}

#define @\defnlibxname{cpp_lib_constexpr_cmath}@ 202306L // also in \libheader{cmath}, \libheader{cstdlib}

#define @\defnlibxname{cpp_lib_constexpr_dynamic_alloc}@ 201907L // also in \libheader{memory}

#define @\defnlibxname{cpp_lib_constexpr_functional}@ 201907L // freestanding, also in \libheader{functional}

#define @\defnlibxname{cpp_lib_constexpr_iterator}@ 201811L // freestanding, also in \libheader{iterator}