Try to watch local variable in watchwindow-DND, too.

Fix codepath overlooked in
6886e485de by introducing
a WatchHandler::watchVariable().

Task-number: QTCREATORBUG-8120
Change-Id: Ibab2619754e0006f3c81810a6bfdf758261c169e
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/watchhandler.cpp

@@ -1586,6 +1586,18 @@ void WatchHandler::watchExpression(const QString &exp, const QString &name)
     updateWatchersWindow();
 }
 
+// Watch something obtained from the editor.
+// Prefer to watch an existing local variable by its expression
+// (address) if it can be found. Default to watchExpression().
+void WatchHandler::watchVariable(const QString &exp)
+{
+    if (const WatchData *localVariable = findCppLocalVariable(exp)) {
+        watchExpression(QLatin1String(localVariable->exp), exp);
+    } else {
+        watchExpression(exp);
+    }
+}
+
 static void swapEndian(char *d, int nchar)
 {
     QTC_ASSERT(nchar % 4 == 0, return);