tree-ssa-uninit: suppress more spurious warnings

tree-ssa-uninit: suppress more spurious warnings

	* tree-ssa-uninit.c (value_sat_pred_p): This new function is a wrapper
        around is_value_included_in that knows how to handle BIT_AND_EXPR.
        (is_pred_expr_subset_of): Use the new function.  Handle more cases where
        code1 == EQ_EXPR and where code1 == BIT_AND_EXPR and thus fix some false
        positives.

testsuite/
        * gcc.dg/uninit-28-gimple.c: New test.
        * gcc.dg/uninit-29-gimple.c: New test.
        * gcc.dg/uninit-30-gimple.c: New test.
        * gcc.dg/uninit-31-gimple.c: New test.

From-SVN: r271460