c11: Improve c99 c11 compat headers
Add c11 compat macro _Static_assert Add c11 compat macro _Noreturn Add c11 compat macro _Thread_local
#include <assert.h> in c11_compat.h to avoid duplicated define static_assert
Judge STDC_VERSION more reliably in c99_compat.h
based on !15497 (merged)
Signed-off-by: Yonggang Luo luoyonggang@gmail.com
Edited by Yonggang Luo