Abort on line numbering or column numbering overflow. Line numbers are limited to values that fit in "unsigned int". Also reject input lines longer than 2^32-1 characters. It seems reasonable to presume that any input that violates these constraints is someone screwing around and not a serious attempt to compile or preprocess anything useful. Done in response to n2129, but without getting into any of the silliness found there.

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