ProjectExplorer: Move ProcessHandle to Utils for further re-use

Also, use qint64 instead of quint64, as this is what Qt uses.

Keep 0 for invalid PIDs, even if arguably -1 would be better,
but Qt uses 0, too.

Don't move 'toString', instead inline it into the only
caller, keeping translations intact.

Task-number: QTCREATORBUG-17596
Change-Id: Ie9411ea1d2031a5ab0a99bcb3ff48ee430afe254
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/libs/utils/processhandle.cpp

@@ -0,0 +1,71 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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 "processhandle.h"
+
+namespace Utils {
+
+/*!
+    \class Utils::ProcessHandle
+    \brief The ProcessHandle class is a helper class to describe a process.
+
+    Encapsulates parameters of a running process, local (PID) or remote (to be
+    done, address, port, and so on).
+*/
+
+// That's the same as in QProcess, i.e. Qt doesn't care for process #0.
+const qint64 InvalidPid = 0;
+
+ProcessHandle::ProcessHandle()
+    : m_pid(InvalidPid)
+{
+}
+
+ProcessHandle::ProcessHandle(qint64 pid)
+    : m_pid(pid)
+{
+}
+
+bool ProcessHandle::isValid() const
+{
+    return m_pid != InvalidPid;
+}
+
+void ProcessHandle::setPid(qint64 pid)
+{
+    m_pid = pid;
+}
+
+qint64 ProcessHandle::pid() const
+{
+    return m_pid;
+}
+
+bool ProcessHandle::equals(const ProcessHandle &rhs) const
+{
+    return m_pid == rhs.m_pid;
+}
+
+} // Utils