ref: b720c03d99ac04c864c68d10bb866fc7807bfccb dir: /sys/src/libc/riscv64/argv0.s/
GLOBL argv0(SB), $XLEN GLOBL _tos(SB), $XLEN GLOBL _privates(SB), $XLEN GLOBL _nprivates(SB), $XLEN