eliminate deprecated_insert_raw_breakpoint. what's left.

[Pedro Alves <palves@redhat.com>]

Hey,

I'm working on a patch that converts software single-step breakpoints
to real breakpoints.  It's largely done, but needs a bit of cleaning up
before I'll post it.  One issue is that software single-step breakpoints
were implemented on top of deprecated_insert_raw_breakpoint.  They no
longer are after my patch, but we're still left with some ugly code in
breakpoint.c related to deprecated_insert_raw_breakpoints on top of other
breakpoints that I'd like to eliminate completely, but that can only
be done once all users of deprecated_insert_raw_breakpoint are either converted
to some more modern mechanism, or eliminated.

Before I go spend some effort blindly trying to do these remaining
conversions, I thought I'd run them through the list first, in case some
of this code can be considered dead already, or in case someone can
lend a hand (which would be awesome).

The remaining users are:

 procfs.c:      dbx_link_bpt = deprecated_insert_raw_breakpoint (target_gdbarch (), NULL,

This is only compiled if SYS_syssgi is defined, which I believe means
MIPS IRIX.  Do we still care about MIPS IRIX?

 solib-irix.c:      base_breakpoint = deprecated_insert_raw_breakpoint (target_gdbarch (),

This could/should probably be converted to use create_solib_event_breakpoint.
Though see above.

 rs6000-nat.c:  bp = deprecated_insert_raw_breakpoint (gdbarch, NULL, DUMMY_INSN_ADDR);

This is AIX code.  Looks like this can easily be converted to a momentary breakpoint?

AFAIR, I have no way to test either AIX or IRIX.

Thanks,
Pedro Alves