ref: 98dba9a4a311dd7b7435a5a5d66619f2a2b4b6cf dir: /sys/src/libc/amd64/argv0.s/
GLOBL argv0(SB), $8 GLOBL _tos(SB), $8 GLOBL _privates(SB), $8 GLOBL _nprivates(SB), $4