Utils: Copy some SynchronousProcess function to QtcProcess

Start using it in Utils::Archive.

The idea is to merge SynchronousProcess into QtcProcess (or avoid its
use) to have fewer classes to make "remote-aware".

Change-Id: Ieb08f6f66eab63fd058b75e3bafa79bfbf140387
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/libs/utils/qtcprocess.cpp

@@ -752,7 +752,7 @@ void QtcProcess::start()
 #endif
         // Note: Arguments set with setNativeArgs will be appended to the ones
         // passed with start() below.
-        QProcess::start(command, QStringList());
+        QProcess::start(command, QStringList(), m_openMode);
     } else {
         if (!success) {
             setErrorString(tr("Error in command line."));
@@ -761,7 +761,7 @@ void QtcProcess::start()
             emit errorOccurred(QProcess::UnknownError);
             return;
         }
-        QProcess::start(command, arguments.toUnixArgs());
+        QProcess::start(command, arguments.toUnixArgs(), m_openMode);
     }
 
     if (m_synchronous)
@@ -1275,6 +1275,22 @@ void QtcProcess::setSynchronous(bool on)
     m_synchronous = on;
 }
 
+void QtcProcess::setOpenMode(OpenMode mode)
+{
+    m_openMode = mode;
+}
+
+bool QtcProcess::stopProcess()
+{
+    if (state() == QProcess::NotRunning)
+        return true;
+    terminate();
+    if (waitForFinished(300))
+        return true;
+    kill();
+    return waitForFinished(300);
+}
+
 bool QtcProcess::ArgIterator::next()
 {
     // We delay the setting of m_prev so we can still delete the last argument