[clang] Ensure that comment classes are trivially destructible

[riccibruno]

Summary

As in D66646, these classes are also allocated with a BumpPtrAllocator, and therefore should be trivially destructible.

[Mordante]

Please also add a test for the DeclInfo struct. It isn't a CommentNode but also allocated with the BumpPtrAllocator.
I also like @gribozavr's input.

[gribozavr]

Regarding adding a test for DeclInfo -- SGTM as well.

[riccibruno]

Also test that DeclInfo is trivially destructible.

Thanks !

clang/lib/AST/Comment.cpp

 //===--- Comment.cpp - Comment AST node implementation --------------------===//
 //
 // 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
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/AST/Comment.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/Basic/CharInfo.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <type_traits>
 
 namespace clang {
 namespace comments {
 
+// Check that no comment class has a non-trival destructor. They are allocated
+// with a BumpPtrAllocator and therefore their destructor is not executed.
+#define ABSTRACT_COMMENT(COMMENT)
+#define COMMENT(CLASS, PARENT)                                                 \
+  static_assert(std::is_trivially_destructible<CLASS>::value,                  \
+                #CLASS " should be trivially destructible!");
+#include "clang/AST/CommentNodes.inc"
+#undef COMMENT
+#undef ABSTRACT_COMMENT
+
+// DeclInfo is also allocated with a BumpPtrAllocator.
+static_assert(std::is_trivially_destructible<DeclInfo>::value,
+              "DeclInfo should be trivially destructible!");
+
 const char *Comment::getCommentKindName() const {
   switch (getCommentKind()) {
   case NoCommentKind: return "NoCommentKind";
 #define ABSTRACT_COMMENT(COMMENT)
 #define COMMENT(CLASS, PARENT) \
   case CLASS##Kind: \
     return #CLASS;
 #include "clang/AST/CommentNodes.inc"