[TableGen] OpInterface inheritance duplicates bases

[darthscsi]

Summary

OpInterface inheritance will duplicate base interfaces, causing compilation failure. Unique the set of base interfaces.

[jdd]

This looks good to me, though I don't know much about the tblgen interface system.

[rriddle]

Looks good to me

mlir/lib/TableGen/Interfaces.cpp

88

I'd expect that to be the default.

[darthscsi]

StringSet change

mlir/lib/TableGen/Interfaces.cpp

 //===- Interfaces.cpp - Interface classes ---------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
Interface::Interface(const llvm::Record *def) : def(def) {
   auto *listInit = dyn_cast<llvm::ListInit>(def->getValueInit("methods"));
   for (llvm::Init *init : listInit->getValues())
     methods.emplace_back(cast<llvm::DefInit>(init)->getDef());
 
   // Initialize the interface base classes.
   auto *basesInit =
       dyn_cast<llvm::ListInit>(def->getValueInit("baseInterfaces"));
   // Chained inheritance will produce duplicates in the base interface set.
-  StringSet<llvm::MallocAllocator> basesAdded;
+  StringSet<> basesAdded;
   llvm::unique_function<void(Interface)> addBaseInterfaceFn =
       [&](const Interface &baseInterface) {
         // Inherit any base interfaces.
         for (const auto &baseBaseInterface : baseInterface.getBaseInterfaces())
           addBaseInterfaceFn(baseBaseInterface);
 
         // Add the base interface.
         if (basesAdded.contains(baseInterface.getName()))