BinaryPredict's equals function compares ignore the op

[yangzhg]

Describe the bug
BinaryPredict's equals function compares ignore the op, the opcode is not init in this class, it will always be INVALID_OPCODE, so if a BinaryPredict has same child it will be qual, like a<1 and a>=1

 @Override
 public boolean equals(Object obj) {
 if (!super.equals(obj)) {
 return false;
 }
 return ((BinaryPredicate) obj).opcode == this.opcode;
 }