Don't assert and leak memory if failing during argument collection. Once you have a -D option or a -include foo option, you need to clean up the arrays those are accumulated in if you die before they're collected and handled.

x
x
x1x
x1x
xx
x12x
t16.c:10:1: Wrong number of arguments for macro c; found 1, expected 2
x1x
t16.c:11:1: Wrong number of arguments for macro c; found 0, expected 2
xx
FAILED