Generate super classes and overridden functions in proper scope

Such references require proper scope so that local symbols are bound.
Example:

```
fun <T> outer() {
    abstract class ALocal<S : T> {
        abstract fun bar()
    }

    class Local<S : T> : ALocal<S>() {
        override fun bar() {}
    }
}
```

Here local classes have type parameters with upper bounds depending on
function type parameters, and members overriding members in other local
classes.

compiler/testData/ir/irText/declarations/localClassWithOverrides.kt

@@ -0,0 +1,13 @@
+fun outer() {
+    abstract class ALocal {
+        abstract fun afun()
+        abstract val aval: Int
+        abstract var avar: Int
+    }
+
+    class Local : ALocal() {
+        override fun afun() {}
+        override val aval = 1
+        override var avar = 2
+    }
+}