Operands of equality expressions are not always mapped #23
Description
When an operand of an equality expression is known to evaluate to null, the mapping of the equality expression is optimized to take this into account. However, as currently implemented, a known-null operand is not mapped at all. This is not correct, since even an operand that is statically known to evaluate to null may have side effects (e.g., if it is an assignment of null or an invocation of a behavior with no return type). So the operands should always be mapped.