FIR2IR: Fix exception when local class used before declaration

compiler/testData/codegen/box/localClasses/localClassUsedBeforeDeclaration.kt

@@ -0,0 +1,6 @@
+fun box(): String {
+    return object {
+        val a = A("OK")
+        inner class A(val ok: String)
+    }.a.ok
+}