ClangTools: Prompt for files to analyze

If the run button is clicked, the user is prompted to select the files
for analysis.

Change-Id: I21e4ee6b7c14392a8c1a901ac7aa1c9c16e30f0d
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/clangtools/clangtoolsunittests.cpp

@@ -131,7 +131,7 @@ void ClangToolsUnitTests::testProject()
         settings->setClangDiagnosticConfigId(clangTidyConfig.id());
     }
 
-    tool->startTool();
+    tool->startTool(false);
     QSignalSpy waiter(tool, SIGNAL(finished(bool)));
     QVERIFY(waiter.wait(30000));