ref: 2bc9e8e5e3b3eab7063c718fc6711b0a1cd14dbe dir: /sys/src/libc/alpha/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4