compilation for files > 2Gb

[Joe Buck]

[ problems with gcc reading multi-gigabyte files because of mmap issues ]

Zack writes:
> Honestly, I cannot think of a legitimate reason why anyone would need
> a C(++) source file that large.  I could be persuaded otherwise with
> an example, but until one arises, I don't see any need to support them
> in GCC.

I agree, there are certainly more pressing problems.  However, if we
aren't going to support it, ideally GCC should produce a message
describing the problem ("File foobar.h is too large to be mapped into
memory" or some such) rather than just fail mysteriously.