RAII-fy make_cleanup_restore_current_thread & friends

RAII-fy make_cleanup_restore_current_thread & friends

After all the make_cleanup_restore_current_thread fixing, I thought
I'd convert that and its relatives (which are all cleanups) to RAII
classes.

scoped_restore_current_pspace_and_thread was put in a separate file to
avoid a circular dependency.

Tested on x86-64 Fedora 23, native and gdbserver.

gdb/ChangeLog:
2017-05-04  Pedro Alves  <palves@redhat.com>

	* Makefile.in (SFILES): Add progspace-and-thread.c.
	(HFILES_NO_SRCDIR): Add progspace-and-thread.h.
	(COMMON_OBS): Add progspace-and-thread.o.
	* breakpoint.c: Include "progspace-and-thread.h".
	(update_inserted_breakpoint_locations)
	(insert_breakpoint_locations, create_longjmp_master_breakpoint):
	Use scoped_restore_current_pspace_and_thread.
	(create_std_terminate_master_breakpoint): Use
	scoped_restore_current_program_space.
	(remove_breakpoint): Use scoped_restore_current_pspace_and_thread.
	(print_breakpoint_location): Use
	scoped_restore_current_program_space.
	(bp_loc_is_permanent): Use
	scoped_restore_current_pspace_and_thread.
	(resolve_sal_pc): Use scoped_restore_current_pspace_and_thread.
	(download_tracepoint_locations): Use
	scoped_restore_current_pspace_and_thread.
	(breakpoint_re_set): Use scoped_restore_current_pspace_and_thread.
	* exec.c (exec_close_1): Use scoped_restore_current_program_space.
	(enum step_over_calls_kind): Moved from inferior.h.
	(class scoped_restore_current_thread): New class.
	* gdbthread.h (make_cleanup_restore_current_thread): Delete
	declaration.
	(scoped_restore_current_thread): New class.
	* infcmd.c: Include "common/gdb_optional.h".
	(continue_1, proceed_after_attach): Use
	scoped_restore_current_thread.
	(notice_new_inferior): Use scoped_restore_current_thread.
	* inferior.c: Include "progspace-and-thread.h".
	(restore_inferior, save_current_inferior): Delete.
	(add_inferior_command, clone_inferior_command): Use
	scoped_restore_current_pspace_and_thread.
	* inferior.h (scoped_restore_current_inferior): New class.
	* infrun.c: Include "progspace-and-thread.h" and
	"common/gdb_optional.h".
	(follow_fork_inferior): Use
	scoped_restore_current_pspace_and_thread.
	(scoped_restore_exited_inferior): New class.
	(handle_vfork_child_exec_or_exit): Use
	scoped_restore_exited_inferior,
	scoped_restore_current_pspace_and_thread,
	scoped_restore_current_thread and scoped_restore.
	(fetch_inferior_event): Use scoped_restore_current_thread.
	* linespec.c (decode_line_full, decode_line_1): Use
	scoped_restore_current_program_space.
	* mi/mi-main.c: Include "progspace-and-thread.h".
	(exec_continue): Use scoped_restore_current_thread.
	(mi_cmd_exec_run): Use scoped_restore_current_pspace_and_thread.
	(mi_cmd_trace_frame_collected): Use scoped_restore_current_thread.
	* proc-service.c (ps_pglobal_lookup): Use
	scoped_restore_current_program_space.
	* progspace-and-thread.c: New file.
	* progspace-and-thread.h: New file.
	* progspace.c (release_program_space, clone_program_space): Use
	scoped_restore_current_program_space.
	(restore_program_space, save_current_program_space)
	(save_current_space_and_thread): Delete.
	(switch_to_program_space_and_thread): Moved to
	progspace-and-thread.c.
	* progspace.h (save_current_program_space)
	(save_current_space_and_thread): Delete declarations.
	(scoped_restore_current_program_space): New class.
	* remote.c (remote_btrace_maybe_reopen): Use
	scoped_restore_current_thread.
	* symtab.c: Include "progspace-and-thread.h".
	(skip_prologue_sal): Use scoped_restore_current_pspace_and_thread.
	* thread.c (print_thread_info_1): Use
	scoped_restore_current_thread.
	(struct current_thread_cleanup): Delete.
	(do_restore_current_thread_cleanup)
	(restore_current_thread_cleanup_dtor): Rename/convert both to ...
	(scoped_restore_current_thread::~scoped_restore_current_thread):
	... this new dtor.
	(make_cleanup_restore_current_thread): Rename/convert to ...
	(scoped_restore_current_thread::scoped_restore_current_thread):
	... this new ctor.
	(thread_apply_all_command): Use scoped_restore_current_thread.
	(thread_apply_command): Use scoped_restore_current_thread.
	* tracepoint.c (tdump_command): Use scoped_restore_current_thread.
	* varobj.c (value_of_root_1): Use scoped_restore_current_thread.