Integrating DWARF2 CFA info

[Andrew Cagney]

> So i've got the dwarf2 CFA info being used now, when available, to
> find the location of a register.

(What exactly does CFA mean.  I know what you're refering to, just not 
the acronym).


> gdbarch functions aren't stackable, so i can't just implement a
> dwarf2_get_saved_register that uses the dwarf2 cfa info, and if it's
> not available, calls the next lower level get_saved_register function.

I don't think a stack is applicable here.  As you move between frames 
the debug info could change and the get_saved_register() functions 
should adapt accordingly.  Having a stack would imply a specific 
heirichy and that isn't correct in this case.

	Andrew