Merge 2024-11 LWG Motion 16

P3309R3 constexpr atomic<T> and atomic_ref<T>

Author: tkoeppe

source/support.tex

@@ -604,6 +604,7 @@
 #define @\defnlibxname{cpp_lib_concepts}@                          202207L
   // freestanding, also in \libheader{concepts}, \libheader{compare}
 #define @\defnlibxname{cpp_lib_constexpr_algorithms}@              202306L // also in \libheader{algorithm}, \libheader{utility}
+#define @\defnlibxname{cpp_lib_constexpr_atomic}@                  202411L // also in \libheader{atomic}
 #define @\defnlibxname{cpp_lib_constexpr_bitset}@                  202207L // also in \libheader{bitset}
 #define @\defnlibxname{cpp_lib_constexpr_charconv}@                202207L // freestanding, also in \libheader{charconv}
 #define @\defnlibxname{cpp_lib_constexpr_cmath}@                   202306L // also in \libheader{cmath}, \libheader{cstdlib}