[DirectX] Update for removal of icmp and fcmp constant expressions

The icmp and fcmp constant expressions were removed in deab451
"[IR] Remove support for icmp and fcmp constant expressions (#93038)".
Update the DXILBitcodeWriter to stop referencing them.

Author: bogner

llvm/lib/Target/DirectX/DXILWriter/DXILBitcodeWriter.cpp

@@ -2160,14 +2160,6 @@ void DXILBitcodeWriter::writeConstants(unsigned FirstVal, unsigned LastVal,
         Record.push_back(VE.getValueID(C->getOperand(1)));
         Record.push_back(VE.getValueID(C->getOperand(2)));
         break;
-      case Instruction::ICmp:
-      case Instruction::FCmp:
-        Code = bitc::CST_CODE_CE_CMP;
-        Record.push_back(getTypeID(C->getOperand(0)->getType()));
-        Record.push_back(VE.getValueID(C->getOperand(0)));
-        Record.push_back(VE.getValueID(C->getOperand(1)));
-        Record.push_back(CE->getPredicate());
-        break;
       }
     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
       Code = bitc::CST_CODE_BLOCKADDRESS;