Change Signature: Support conversion between extension and non-extension functions

idea/testData/refactoring/changeSignature/AddReceiverToGenericsWithOverridesBefore.kt

@@ -0,0 +1,17 @@
+class U<A>
+
+trait T<A> {
+    fun <caret>foofoofoo<B>(a: A, b: B): Int
+}
+
+abstract class T1<X> : T<U<X>> {
+    override fun <B> foofoofoo(a: U<X>, b: B): Int {
+        throw UnsupportedOperationException()
+    }
+}
+
+abstract class T2 : T1<String>() {
+    override fun <C> foofoofoo(a: U<String>, b: C): Int {
+        throw UnsupportedOperationException()
+    }
+}