LLVM Clang 19 Adds Initial "-std=c2y" Support For The Next C Standard

LLVM Clang 19 now includes initial support for the -std=c2y and -std=gnu2y options, aligning with the forthcoming C programming language standard potentially named 'C26'. This early support updates the __STDC_VERSION__ macro to 202400L. The development can be monitored through the C status page, as the new standard evolves beyond C23.