Adjusts printfmt's va_list code for amd64

We can't pass a pointer to a va_list on amd64.  There is a mismatch
between a va_list** and a va_list*[1].

We also don't want to use va_copy, since we want the original va_list to
be modified by getint().

For more info:
	http://www.bailopan.net/blog/?p=30
	http://stackoverflow.com/questions/4958384/what-is-the-format-of-the-x86-64-va-list-structure
	http://stackoverflow.com/questions/3369588/pass-va-list-or-pointer-to-va-list
Splits x86 into 32 and 64 bit (XCC)

No real change in functionality, just separating out the bit-specific items
within the arch directory and build process.

This builds and links in 64 bit mode, but doesn't actually do anything (like
jump into longmode, etc).