Remove unnecessary classof()'s

isa<> et al. automatically infer when the cast is an upcast (including a
self-cast), so these are no longer necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165767 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/MC/MCSectionMachO.h

@@ -174,7 +174,6 @@ public:
   static bool classof(const MCSection *S) {
     return S->getVariant() == SV_MachO;
   }
-  static bool classof(const MCSectionMachO *) { return true; }
 };
 
 } // end namespace llvm