Conform functions to extension functions and vice versa

#KT-5989 Fixed

compiler/testData/diagnostics/tests/resolve/invoke/errors/receiverPresenceErrorForInvoke.kt

@@ -5,7 +5,7 @@ fun test1(f: String.() -> Unit) {
 }
 
 fun test2(f: (Int) -> Int) {
-    1.<!UNRESOLVED_REFERENCE!>f<!>(2)
+    1.f(<!TOO_MANY_ARGUMENTS!>2<!>)
 
-    2.<!NO_RECEIVER_ALLOWED!>(f)<!>(2)
-}
+    2.(f)(<!TOO_MANY_ARGUMENTS!>2<!>)
+}