New macro expander preamble

[Neil Booth]

Zack Weinberg wrote:-

> BTW, there's an interesting bug:
> 
> $ ./cpp0 -Wall - /dev/null
> abcdef??<
> ^D
> <stdin>:1:2: warning: trigraph ??< ignored
> <stdin>:1:2: warning: trigraph ??< ignored
> 
> Seems to happen for any trigraph except when it occurs at the very
> beginning of a line.  dg.exp won't catch this, by the way.

I take it you're referring to the reported column number?

Neil.