ref: 72819dcccff346a919f36f8cb8b1ab2014ab4977
dir: /lib/thread/exit+freebsd-x64.s/
/* const thread.exit : (stacksz : std.size -> void) */ .globl thread$exit thread$exit: /* munmap(base, size) */ movq $73,%rax /* munmap */ movq %fs:0x08,%rdi /* base */ movq %fs:0x10,%rsi /* stksz */ syscall /* thr_exit(null) */ movq $431,%rax /* exit */ xorq %rdi,%rdi /* 0 */ syscall