mips memory sizing in libgloss

[DJ Delorie]

> I haven't the mips expertise to review this.  I might suggest you
> run it past one or more of the previous maintainers of cma101.c if
> you are looking for any potential oversights in your logic.
> Assuming you have tested the change and there are no other
> objections, consider this approval to apply.

It's an old file, with old changes.  I was hoping someone would pipe
up with some history, but if not, we can make new history ;-)