ref: 9fda8c6d9d2723116d9ecfc8f62d3ae2ac1308ea dir: /sys/src/libc/amd64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4