gdb/120: Cleanup software single step.

[ac131313@cygnus.com]

>Number:         120
>Category:       gdb
>Synopsis:       Cleanup software single step.
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    unassigned
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 06 19:58:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     ac131313@cygnus.com
>Release:        unknown-1.0
>Organization:
>Environment:

>Description:
Cleanup software single step.

At present many targets implement software single step by directly
blatting memory (see rs6000-tdep.c).  Those targets should register
the applicable breakpoints using the breakpoint framework.  Perhaphs a
new internal breakpoint class ``step'' is needed.
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: