ref: 9c0d74e03620811e9a5c0a697a849f9c3551e9bf dir: /sys/src/libc/arm64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4