[RFA 2/3] Demote to sw watchpoint only in update_watchpoint

[Eli Zaretskii]

> From: Pedro Alves <pedro@codesourcery.com>
> Date: Tue, 3 May 2011 19:12:42 +0100
> Cc: bauerman@br.ibm.com,
>  uweigand@de.ibm.com
> 
> I'm proposing getting rid of target_can_use_hardware_watchpoint
> as being part of the core accounting infrastructure.

I'm fine with heading that way.  It will certainly be cleaner than the
current mess, which needs a face-lift every few months.