jump.c: Update comments.

jump.c: Update comments.

	* jump.c: Update comments.
	(delete_barrier_successors, delete_unreferenced_labels,
	delete_noop_moves, tension_vector_labels, delete_from_jump_chain,
	delete_labelref_insn, redirect_tablejump, jump_optimize_1,
	jump_optimize, jump_optimize_minimal): Kill.
	(rebuild_jump_labels): Move code from jump_optimize_1.
	(purge_line_number_notes): Likewise.
	(copy_loop_headers): Likewise.
	* reg-stack.c: Update comment.
	* stmt.c: Likewise.
	* rtl.h (jump_optimize, jump_optimize_1, JUMP_NOOP_MOVES,
	JUMP_AFTER_REGSCAN): Kill.
	* toplev.c (rest_of_compilation): Use cleanup_cfg, call
	purge_line_number_notes and copy_loop_headers.

From-SVN: r44245