Add actual: handle already existing declarations more precisely

#KT-23693 Fixed

idea/testData/multiModuleQuickFix/classFunctionSameSignature/common/common.kt

@@ -0,0 +1,5 @@
+// DISABLE-ERRORS
+
+expect object O {
+    fun <T : Any> hello(): MutableMap<String, T>
+}

idea/testData/multiModuleQuickFix/classFunctionSameSignature/common/common.kt.after

@@ -0,0 +1,5 @@
+// DISABLE-ERRORS
+
+expect object O {
+    fun <T : Any> hello(): MutableMap<String, T>
+}