Re: read_register_byte can't work with pseudo-reg model

[Andrew Cagney <ac131313@cygnus.com>]

> The only assumption is that if this is defined, then pseudos do not need 
> unique entries in the regcache (ie they always map onto physical 
> registers), so we can copy the regcache simply by iterating over 
> 0..NUM_REGS.

So the [0..NUM_REGS) space is mapped 1:1, sounds good.

Just resist the temptation to look under the following rock: 
0..NUM_REGS will include hardware registers save/restoring that probably 
isn't a good idea.  Per other e-mail, it will eventually need to check 
if the register should be saved/restored.

I think I'll tweak that branch to, when restoring the cache and 
register_write_p, not call write_register_bytes().

> I need to re-baseline my testsuite runs, but the results look pretty 
> encouraging compared to previous runs.

Andrew