Factor predidacte analysis out of tree-ssa-uninit.c into its own module.

gcc/ChangeLog:

	* Makefile.in (OBJS): Add gimple-predicate-analysis.o.
	* tree-ssa-uninit.c (max_phi_args): Move to gimple-predicate-analysis.
	(MASK_SET_BIT, MASK_TEST_BIT, MASK_EMPTY): Same.
	(check_defs): Add comment.
	(can_skip_redundant_opnd): Update comment.
	(compute_uninit_opnds_pos): Adjust to namespace change.
	(find_pdom): Move to gimple-predicate-analysis.cc.
	(find_dom): Same.
	(struct uninit_undef_val_t): New.
	(is_non_loop_exit_postdominating): Move to gimple-predicate-analysis.cc.
	(find_control_equiv_block): Same.
	(MAX_NUM_CHAINS, MAX_CHAIN_LEN, MAX_POSTDOM_CHECK): Same.
	(MAX_SWITCH_CASES): Same.
	(compute_control_dep_chain): Same.
	(find_uninit_use): Use predicate analyzer.
	(struct pred_info): Move to gimple-predicate-analysis.
	(convert_control_dep_chain_into_preds): Same.
	(find_predicates): Same.
	(collect_phi_def_edges): Same.
	(warn_uninitialized_phi): Use predicate analyzer.
	(find_def_preds): Move to gimple-predicate-analysis.
	(dump_pred_info): Same.
	(dump_pred_chain): Same.
	(dump_predicates): Same.
	(destroy_predicate_vecs): Remove.
	(execute_late_warn_uninitialized): New.
	(get_cmp_code): Move to gimple-predicate-analysis.
	(is_value_included_in): Same.
	(value_sat_pred_p): Same.
	(find_matching_predicate_in_rest_chains): Same.
	(is_use_properly_guarded): Same.
	(prune_uninit_phi_opnds): Same.
	(find_var_cmp_const): Same.
	(use_pred_not_overlap_with_undef_path_pred): Same.
	(pred_equal_p): Same.
	(is_neq_relop_p): Same.
	(is_neq_zero_form_p): Same.
	(pred_expr_equal_p): Same.
	(is_pred_expr_subset_of): Same.
	(is_pred_chain_subset_of): Same.
	(is_included_in): Same.
	(is_superset_of): Same.
	(pred_neg_p): Same.
	(simplify_pred): Same.
	(simplify_preds_2): Same.
	(simplify_preds_3): Same.
	(simplify_preds_4): Same.
	(simplify_preds): Same.
	(push_pred): Same.
	(push_to_worklist): Same.
	(get_pred_info_from_cmp): Same.
	(is_degenerated_phi): Same.
	(normalize_one_pred_1): Same.
	(normalize_one_pred): Same.
	(normalize_one_pred_chain): Same.
	(normalize_preds): Same.
	(can_one_predicate_be_invalidated_p): Same.
	(can_chain_union_be_invalidated_p): Same.
	(uninit_uses_cannot_happen): Same.
	(pass_late_warn_uninitialized::execute): Define.
	* gimple-predicate-analysis.cc: New file.
	* gimple-predicate-analysis.h: New file.