128 bit signed and unsigned integer types

[dsimcha]

== Quote from Walter Bright (newshound1 at digitalmars.com)'s article
> You know, the unimplemented 128 bit integer types.
> Does anyone have a use for these?

Well, we've got bigints in both Phobos and Tango now.  Given the clumsiness or
downright impossibility of manipulating 128-bit ints in hardware on x86-32, would
they even be much faster than bigints?  I mean, you couldn't even fit 2 128-bit
ints plus a stack pointer in the general-purpose registers of an x86.