Revert "Revert "Merge remote-tracking branch 'origin/4.15'""

This reverts commit f0a86d4510.

Reverting a merge doesn't "undo" it - the changes would be lost
forever even with subsequent merges.
So we need to revert the revert to get the changes.

Change-Id: I65928f876f4dc886561bed17c4b2aa42b388c1e3
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/libs/sqlite/sqlitelibraryinitializer.cpp

@@ -0,0 +1,47 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "sqlitelibraryinitializer.h"
+
+#include "sqlitedatabasebackend.h"
+
+namespace Sqlite {
+
+void LibraryInitializer::initialize()
+{
+    static LibraryInitializer initializer;
+}
+
+LibraryInitializer::LibraryInitializer()
+{
+    DatabaseBackend::initializeSqliteLibrary();
+}
+
+LibraryInitializer::~LibraryInitializer()
+{
+    DatabaseBackend::shutdownSqliteLibrary();
+}
+
+} // namespace Sqlite