Do not run unused symbol inspection on default objects for now

#KT-6872 Fixed

idea/testData/inspections/unusedSymbol/object/defaultObject.kt

@@ -0,0 +1,23 @@
+package defaultObject
+
+class A {
+    class object {
+    }
+}
+
+class B {
+    class object NamedUnused {
+    }
+}
+
+class C {
+    class object NamedUsed {
+    }
+}
+
+fun main(args: Array<String>) {
+    A()
+    B()
+    C()
+    C.NamedUsed
+}