[flang][NFC] Remove unused DispatchTableop fct

[clementval]

Summary

Remove appendTableEntry as it is not used.

[jeanPerier]

LGTM

[PeteSteinfeld]

All builds and tests correctly and looks good.

flang/include/flang/Optimizer/Dialect/FIROps.td

def fir_DispatchTableOp : fir_Op<"dispatch_table",
   let skipDefaultBuilders = 1;
   let builders = [
     OpBuilder<(ins "llvm::StringRef":$name, "mlir::Type":$type,
       "llvm::StringRef":$parent,
       CArg<"llvm::ArrayRef<mlir::NamedAttribute>", "{}">:$attrs)>
   ];
 
   let extraClassDeclaration = [{
-    /// Append a dispatch table entry to the table.
-    void appendTableEntry(mlir::Operation *op);
-
     static constexpr llvm::StringRef getParentAttrNameStr() { return "parent"; }
     static constexpr llvm::StringRef getExtendsKeyword() { return "extends"; }
 
     mlir::Block &getBlock() {
       return getRegion().front();
     }
   }];
 }

flang/lib/Optimizer/Dialect/FIROps.cpp

mlir::FunctionType fir::DispatchOp::getFunctionType() {
   return mlir::FunctionType::get(getContext(), getOperandTypes(),
                                  getResultTypes());
 }
 
 //===----------------------------------------------------------------------===//
 // DispatchTableOp
 //===----------------------------------------------------------------------===//
 
-void fir::DispatchTableOp::appendTableEntry(mlir::Operation *op) {
-  assert(mlir::isa<fir::DTEntryOp>(*op) && "operation must be a DTEntryOp");
-  auto &block = getBlock();
-  block.getOperations().insert(block.end(), op);
-}
-
 mlir::ParseResult fir::DispatchTableOp::parse(mlir::OpAsmParser &parser,
                                               mlir::OperationState &result) {
   // Parse the name as a symbol reference attribute.
   mlir::StringAttr nameAttr;
   if (parser.parseSymbolName(nameAttr, mlir::SymbolTable::getSymbolAttrName(),
                              result.attributes))
     return mlir::failure();