Implementation of super methods calling (#203)

* implemented super call

* tests

* removed redundant code

backend.native/tests/codegen/basics/superGetterCall.kt

@@ -0,0 +1,19 @@
+open class C {
+    open val p1 = "<prop:C>"
+}
+
+class C1: C() {
+    override val p1 = super<C>.p1 + "<prop:C1>"
+}
+
+open class C2: C() {
+}
+
+class C3: C2() {
+    override val p1 = super<C2>.p1 + "<prop:C3>"
+}
+
+fun main(args: Array<String>) {
+    println(C1().p1)
+    println(C3().p1)
+}