Hey guys, How likely would the standard be to accept a proposal to add compile time reflection to the preprocessor, or even adopt C++'s constexpr? My use case

Hey guys, How likely would the standard be to accept a proposal to add compile time reflection to the preprocessor, or even adopt C++'s constexpr? My use case is creating a global array in a header from static compound literals in multiple source files at compile time, and outside of some crazy clang-tblgen type solution, or very platform specific linker hacks, it's completely unsupported by C.