[RFC] Changes to *_*regset functions

[Andrew Cagney]

> Along with the cross-core handling, and eventually cross-thread support, I
> want to multi-arch supply_gregset/fill_gregset/supply_fpregset/fill_fpregset,
> and make them target rather than native functions where possible.  The issue,
> of course, is that the *regset_t and *reg_t types are not available to us
> when cross compiling, and attempting to make them available seems the wrong
> way to go.


Do they belong in gdbarch?  gdbarch contains things that describe the 
target systems ISA, ABI, ...

Something like supply_gregset() might use gdbarch.  I don't know that it 
belongs in multi-arch.

	Andrew