ref: 1b7e6fefc6a60755b03d36b3e00a7318c8b2e747 dir: /sys/src/libc/amd64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4