Debugger: Streamline ramping down

There were only two used target states, and in case of mixed
debugging all parts of the machinery better agree on the
direction. So one bool in the (shared) runTool is sufficient.

Change-Id: Iffbf1651b82dde707cfc37d8da9d3da573b34b76
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/gdb/gdbengine.cpp

@@ -272,7 +272,7 @@ QString GdbEngine::errorMessage(QProcess::ProcessError error)
                 "permissions to invoke the program.\n%2")
                 .arg(runParameters().debugger.executable, m_gdbProc.errorString());
         case QProcess::Crashed:
-            if (targetState() == DebuggerFinished)
+            if (isDying())
                 return tr("The gdb process crashed some time after starting "
                     "successfully.");
             else
@@ -4085,7 +4085,7 @@ void GdbEngine::handleGdbFinished(int exitCode, QProcess::ExitStatus exitStatus)
 
 void GdbEngine::abortDebugger()
 {
-    if (targetState() == DebuggerFinished) {
+    if (isDying()) {
         // We already tried. Try harder.
         showMessage("ABORTING DEBUGGER. SECOND TIME.");
         m_gdbProc.kill();