Clang: Workaround completion for make_unique/shared

Change unsaved file to provide constructor overloads
for std::make_unique, std::make_shared and
QSharedPointer::create

Example:
// Provide Foo constructor signatures at <Cursor>
std::make_unique<Foo>(<Cursor>

Task-number: QTCREATORBUG-18615
Change-Id: I87dd17085adf99ee498db969a3cdda5ebd973476
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

tests/unit/unittest/data/complete_smartpointer.cpp

@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 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.
+**
+****************************************************************************/
+namespace std {
+template<class Type, class... Args>
+class unique_ptr {};
+
+template<class Type, class... Args>
+class shared_ptr {};
+
+template<class Type, class... Args>
+unique_ptr<Type> make_unique(Args&&... args);
+
+template<class Type, class... Args>
+shared_ptr<Type> make_shared(Args&&... args);
+} // namespace std
+
+template<class Type>
+class QSharedPointer
+{
+public:
+    template<class... Args>
+    static QSharedPointer<Type> create(Args&&... args);
+};
+
+class Bar
+{
+public:
+    Bar();
+    Bar(int, int);
+};
+void f2()
+{
+    std::unique_ptr<Bar> bar = std::make_unique<Bar>();
+    std::shared_ptr<Bar> bar2 = std::make_shared<Bar>();
+    QSharedPointer<Bar> bar3 = QSharedPointer<Bar>::create();
+}