SQL Server: use XOR to translate some == and != expressions #34124

When the parent expression is not a predicate, translate `x != y` to: ```sql x ^ y ``` instead of ```sql CASE WHEN x <> y THEN CAST(1 AS bit) ELSE CAST(0 AS bit) END ``` Similarly, translate `x == y` to: ```sql x ^ y ^ CAST(1 AS bit) ``` instead of ```sql CASE WHEN x == y THEN CAST(1 AS bit) ELSE CAST(0 AS bit) END ``` Contributes to dotnet#34001 for simple cases (comparison of BIT expressions).