CPlusPlus: Support associating comments with a declaration

This will serve as the basic building block for several comment-related
features.

Task-number: QTCREATORBUG-6934
Task-number: QTCREATORBUG-12051
Task-number: QTCREATORBUG-13877
Change-Id: Ic68587c0d7985dc731da9f539884590fcec764de
Reviewed-by: David Schulz <david.schulz@qt.io>

src/libs/cplusplus/declarationcomments.h

@@ -0,0 +1,21 @@
+// Copyright (C) 2023 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+#include <cplusplus/Token.h>
+
+#include <QList>
+
+QT_BEGIN_NAMESPACE
+class QTextDocument;
+QT_END_NAMESPACE
+
+namespace CPlusPlus {
+class Snapshot;
+
+QList<Token> CPLUSPLUS_EXPORT commentsForDeclaration(const Symbol *symbol,
+                                                     const Snapshot &snapshot,
+                                                     const QTextDocument &textDoc);
+
+} // namespace CPlusPlus