Attached is a patch that uses autoconf to determine whether there

is a working 64-bit-int type available.

In playing around with it on my machine, I found that gcc provides
perfectly fine support for "long long" arithmetic ... but sprintf()
and sscanf(), which are system-supplied, don't work :-(.  So the
autoconf test program does a cursory test on them too.

If we find that a lot of systems are like this, it might be worth
the trouble to implement binary<->ASCII conversion of int64 ourselves
rather than relying on sprintf/sscanf to handle the data type.

			regards, tom lane