fondling macros.
* (trap_low): Save and restore FP regs if necessary. Also, clean
up save and restore of debug unit regs.
* (hard_trap_info): Add more architecturally defined traps.
* (set_debug_traps): Only set FP disabled trap if FP is disabled.
* (get_in_break_mode): Clean up. Get rid of calls to
set_hw_breakpoint_trap(). Also, use write_asi macro
* (handle_exception): Clean up `g' and `G' commands. Add `P'
command.
* (hw_breakpoint): Why was this here!? It's gone now...
