BRISTOL-MYERS SQUIBB COMPANY, Plaintiff-Appellee, v. RHONE-POULENC RORER, INC., Rhone-Poulenc Rorer, S.A., and Centre National De La Recherche Scientifique, Defendants-Appellants; Rhone-Poulenc Rorer, Inc. and Rhone-Poulenc Rorer, S.A., Plaintiffs/Counterclaim Defendants-Appellants, and Centre National De La Recherche Scientifique, Counterclaim Defendant-Appellant, v. Bristol-Myers Squibb Company, Defendant/Counterclaimant-Appellee