tests: let tst_dumpers compile with Qt4

Change-Id: I34851ebfc054f0f8265e5ce1623e0db956aab085
Reviewed-by: hjk <hjk121@nokiamail.com>

tests/auto/debugger/tst_dumpers.cpp

@@ -34,8 +34,7 @@
 #include <CppRewriter.h>
 
 #include <QtTest>
-#include <QTemporaryFile>
-#include <QTemporaryDir>
+#include "temporarydir.h"
 
 using namespace Debugger;
 using namespace Internal;