m1lkweed

#pragma once
// (c) M1lkweed, 2022-2023
// Released as GPLv3+

// Differences from normal setjmp:
// 1.) volatile is not required to prevent clobbering
// 2.) sizeof(xjmp_buf) is 8
// 3.) xlongjmp can be used more than once per buffer
// 4.) reading the return value of xsetjmp is not UB
// 5.) all of the points also apply to the sig*jmp family