emit-rtl.c (immed_double_const): Use gcc_assert and gcc_unreachable.

emit-rtl.c (immed_double_const): Use gcc_assert and gcc_unreachable.

	* emit-rtl.c (immed_double_const): Use gcc_assert and gcc_unreachable.
	(gen_rtx_SUBREG, gen_reg_rtx, mark_user_reg, subreg_hard_regno,
	gen_lowpart_common, gen_highpart, gen_highpart_mode,
	subreg_highpart_offset, operand_subword, operand_subword_force,
	mem_expr_equal_p, set_mem_attributes_minus_bitpos,
	set_mem_alias_set, change_address_1, verify_rtx_sharing,
	copy_most_rtx, set_first_insn, set_last_insn, prev_cc0_setter,
	try_split, add_insn_after, add_insn_before, remove_insn,
	remove_unnecessary_notes, emit_insn_before, emit_jump_insn_before,
	emit_call_insn_before, emit_insn_after, emit_jump_insn_after,
	emit_call_insn_after, emit_insn, emit_jump_insn, emit_call_insn,
	set_unique_reg_note, emit, push_to_full_sequence, copy_insn_1,
	gen_const_vector_0, emit_copy_of_insn_after): Likewise.
	* et-forest.c (set_prev, set_next, et_check_occ_sanity,
	record_path_before_1, check_path_after_1, check_path_after): Likewise.
	* except.c (gen_eh_region, resolve_one_fixup_region,
	remove_unreachable_regions, convert_from_eh_region_ranges_1,
	add_ehl_entry, duplicate_eh_region_1, build_post_landing_pads,
	connect_post_landing_pads, sjlj_emit_function_exit,
	remove_exception_handler_label, remove_eh_handler,
	reachable_next_level, collect_one_action_chain,
	output_function_exception_table): Likewise.
	* explow.c (trunc_int_for_mode, copy_to_mode_reg,
	optimize_save_area_alloca, allocate_dynamic_stack_space,
	probe_stack_range, hard_function_value): Likewise.
	* expmed.c (mode_for_extraction, store_bit_field,
	store_fixed_bit_field, extract_bit_field, expand_shift,
	expand_mult_const, expand_mult, choose_multiplier,
	expand_mult_highpart, expand_divmod, emit_store_flag,
	do_cmp_and_jump): Likewise.
	* expr.c (convert_move, convert_modes, move_by_pieces,
	move_by_pieces_ninsns, move_by_pieces_1, emit_block_move,
	move_block_from_reg, gen_group_rtx, emit_group_load,
	emit_group_move, emit_group_store, use_reg, use_regs,
	can_store_by_pieces, store_by_pieces, store_by_pieces_1,
	emit_move_insn, emit_move_insn_1, emit_push_insn,
	expand_assignment, store_expr, count_type_elements,
	store_constructor, store_field, safe_from_p, expand_var,
	expand_expr_addr_expr, expand_expr_real_1, do_store_flag): Likewise.

From-SVN: r87178