Fix #13236: False positive: unusedFunction reported when SLOT() is used in qt code

Author: olabetskyi

cfg/qt.cfg

@@ -59,8 +59,8 @@
   <reflection>
     <call arg="2">invokeMethod</call>
   </reflection>
-  <define name="SIGNAL(X)" value="#X"/>
-  <define name="SLOT(X)" value="#X"/>
+  <!-- <define name="SIGNAL(X)" value="#X"/> -->
+  <!-- <define name="SLOT(X)" value="#X"/> -->
   <!-- T qAbs(const T &t) -->
   <function name="qAbs">
     <pure/>

test/cfg/qt.cpp

@@ -811,4 +811,15 @@ struct BQObject_missingOverride { // #13406
 
 struct DQObject_missingOverride : BQObject_missingOverride {
     Q_OBJECT
-};
+};
+
+class Foo { // #13236
+    Foo();
+    void dostuff();
+};
+
+Foo::Foo() {
+    connect(a, SIGNAL(dostuff()), this, SLOT(dostuff()));
+}
+
+void Foo::dostuff() {} // Should not warn here with unusedFunction