ref: 963cfc9a6f6e721f52aa949e6d1af0c3e8dc2ecc dir: /sys/src/libc/amd64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4