[RFA] Add some VAX floating point formats to floatformat.[ch]

[Nick Clifton]

Hi Mark,

> Index: include/ChangeLog
> from  Mark Kettenis  <kettenis@gnu.org>
> 
> 	* floatformat.h (enum floatformat_byteorders): Add
> 	floatformat_vax.
> 	(floatformat_vax_aingle, floatformat_vax_double): Declare.

No objections from binutils for this, although it is officially a GDB 
header file so make sure that you get agreement from them before 
committing your change.  One point though:

> +  /* VAX byte order.  */
> +  floatformat_vax

I think that having a more descriptive comment for the VAX byte order 
would be helpful.  eg describing the layout of 1.2345678e10 as is done 
with the other entries in this enum.

Cheers
   Nick