df-core.c (df_set_blocks): Use bitmap_head instead of bitmap.

	* df-core.c (df_set_blocks): Use bitmap_head instead of bitmap.
	(df_compact_blocks): Likewise.
	* df.h (struct df): Turn hardware_regs_used,
	regular_block_artificial_uses, eh_block_artificial_uses,
	insns_to_delete, insns_to_rescan, insns_to_notes_rescan into
	bitmap_head.
	* df-problems.c (df_lr_local_compute, df_lr_confluence_0,
	df_byte_lr_alloc, df_simulate_fixup_sets): Update.
	* df-scan.c (df_scan_free_internal, df_scan_alloc, df_scan_start_dump,
	df_scan_blocks, df_insn_delete, df_insn_rescan,
	df_insn_rescan_debug_internal, df_insn_rescan_all,
	df_process_deferred_rescans, df_process_deferred_rescans,
	df_notes_rescan, df_get_call_refs, df_get_call_refs,
	regs_invalidated_by_call_regset, df_get_call_refs, df_bb_refs_collect,
	df_record_entry_block_defs, df_record_exit_block_uses,
	df_update_exit_block_uses, df_bb_verify, df_entry_block_bitmap_verify,
	df_scan_verify): Update.

From-SVN: r160348