[InstCombine] Remove unnecessary typed pointer fold (NFCI)

Pointer bitcasts will be optimized away, no need to fold them for
icmps in particular.

Author: nikic

llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp

@@ -3258,18 +3258,6 @@ Instruction *InstCombinerImpl::foldICmpBitCast(ICmpInst &Cmp) {
     }
   }
 
-  // Test to see if the operands of the icmp are casted versions of other
-  // values. If the ptr->ptr cast can be stripped off both arguments, do so.
-  if (DstType->isPointerTy() && (isa<Constant>(Op1) || isa<BitCastInst>(Op1))) {
-    // If operand #1 is a bitcast instruction, it must also be a ptr->ptr cast
-    // so eliminate it as well.
-    if (auto *BC2 = dyn_cast<BitCastInst>(Op1))
-      Op1 = BC2->getOperand(0);
-
-    Op1 = Builder.CreateBitCast(Op1, SrcType);
-    return new ICmpInst(Pred, BCSrcOp, Op1);
-  }
-
   const APInt *C;
   if (!match(Cmp.getOperand(1), m_APInt(C)) || !DstType->isIntegerTy() ||
       !SrcType->isIntOrIntVectorTy())