ref: 6c00c9b0876ee6d96aa76e11854d0ff8ed8c4dbe dir: /sys/src/libc/amd64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4