Added VisitorGetUsefulEqs that helps to onnly keep potentially useful equalities of new equalities extrcted from instantiations, integrated it in the instantiation process.
Added VisitorGetUsefulEqs that helps to onnly keep potentially useful equalities of new equalities extrcted from instantiations, integrated it in the instantiation process.

CompOpt4Apps/IEGenLib,CompOpt4Apps/IEGenLib,CompOpt4Apps/IEGenLib,CompOpt4Apps/IEGenLib,CompOpt4Apps/IEGenLib,CompOpt4Apps/IEGenLib,CompOpt4Apps/IEGenLib