[FE] Prohibit expect fun interface to have non-fun actual counterpart

In K1 .isFun is always false for Java classes, so extra check
is added for that. This is not needed for K2, because .isFun is
true for all Java classes. Here it is not necessary to check
that interface has only one method, because such check will be
done in the place where interface implementation is created.

^KT-39362 Fixed

core/compiler.common/src/org/jetbrains/kotlin/resolve/multiplatform/ExpectActualCompatibility.kt

@@ -65,6 +65,8 @@ sealed class ExpectActualCompatibility<out D> {
 
         object ClassModifiers : Incompatible<Nothing>("modifiers are different (companion, inner, inline)")
 
+        object FunInterfaceModifier : Incompatible<Nothing>("actual declaration for fun expect interface is not a functional interface")
+
         object Supertypes : Incompatible<Nothing>("some supertypes are missing in the actual declaration")
 
         class ClassScopes<D>(