Add toString() to Any, fix all tests

#KT-4517 Fixed

idea/testData/codeInsight/overrideImplement/inheritVisibilities.kt.after

@@ -30,4 +30,7 @@ class C : A(), B {
         super<A>.publicFun()
     }
     override val publicProperty: Int = 0
+    override fun toString(): String {
+        return super<A>.toString()
+    }
 }