Problem:
When inferring predicate，we lost cast of source expressions and some datatype derivation.
Example:
a = b and cast(a as targetType) = constant
(cast(a as targetType) = constant ) this expression is define as source expression.
we expect getting cast(b as targetType) = constant instead of b = constant
Reason:
When inferring predicate, we will compare original type of a and b. if they can be cast
without precision lost, a new predicate would be created. But created predicate forgot
to cast to target type
Solved:
Add cast to target type, and open make other datatype valid also.
be3618316f