ref: e1cc6a9a0f0ebbcbb32f177cfc2c977509cbb6fb dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4