"enter_vararg" is like doing the following:
enter_vararg:
dim params[*]
local x
enter x, err=*return; params[*] = x
enter *, x, err=*return; params[*] = x
enter *, *, x, err=*return; params[*] = x
enter *, *, *, x, err=*return; params[*] = x
enter *, *, *, *, x, err=*return; params[*] = x
! ...
return