selected_frame_address and selected_level with field
selected_frame_id.
(save_inferior_status): Update. Use get_frame_id.
(struct restore_selected_frame_args): Delete.
(restore_selected_frame): Update. Use frame_find_by_id.
(restore_inferior_status): Update.
* breakpoint.h (struct breakpoint): Change type of
watchpoint_frame to frame_id.
* breakpoint.c (insert_breakpoints): Use frame_find_by_id. Remove
call to get_current_frame.
(do_enable_breakpoint): Use frame_find_by_id. Remove call to
get_current_frame.
(watchpoint_check): Use frame_find_by_id.
* frame.h (record_selected_frame): Delete declaration.
* stack.c (record_selected_frame): Delete function.
* frame.h (struct frame_id): Define.
(get_frame_id): Declare.
(frame_find_by_id): Declare.
* frame.c (frame_find_by_id): New function.
(get_frame_id): New function.
saved_regs. Mention when the SP is on the stack or in a register.
* frame.h (frame_register_unwind_ftype): Define. Document.
(struct frame_info): Add field register_unwind and
register_unwind_cache.
(frame_register_unwind): Declare.
(generic_unwind_get_saved_register): Declare.
* frame.c (frame_register_unwind): New function.
(generic_unwind_get_saved_register): New function.
* blockframe.c (generic_call_dummy_register_unwind): New function.
(frame_saved_regs_register_unwind): New function.
(set_unwind_by_pc): New function.
(create_new_frame): New function.
(get_prev_frame): New function.
