Unifying i387 support

[Eli Zaretskii]

> As I understand it, there are multiple ways to interpret the contents
> of an MMX register.  It might contain one double, or two floats.

AFAIK, the MMX registers only contain integers, not floats.

> And
> only the user knows what is appropriate at any given time.  I can't
> tell if this impinges on our choice of register layout.  Does anyone
> have any idea how to handle this?

If the MMX registers contain integers, as I think they do, simply
displaying them in hex and decimal as we do with EAX will be good
enough.

It seems like this belongs to "info all-registers", not to "info
float", though.