"The joint opinion, following its newly-minted variation on stare decisis, retains the outer shell of Roe v. Wade, 410 U.S. 113, 93 S.Ct. 705, 35 L.Ed.2d 147 (1973), but beats a wholesale retreat from the substance of that case. We believe that Roe was wrongly decided, and that it can and should be overruled consistently with our traditional approach to stare decisis in constitutional cases. We would adopt the approach of the plurality in Webster v. Reproductive Health Services, 492 U.S. 490, 109 S.Ct. 3040, 106 L.Ed.2d 410 (1989), and uphold the challenged provisions of the Pennsylvania statute in their entirety."