Fix codegen for multifile class parts with type aliases only

#KT-20337 Fixed

compiler/testData/compileKotlinAgainstKotlin/multifileClassWithTypealias.kt

@@ -0,0 +1,16 @@
+// IGNORE_BACKEND: NATIVE
+// FILE: A.kt
+
+@file:[JvmName("Test") JvmMultifileClass]
+
+typealias S = String
+typealias LS = List<S>
+
+// FILE: B.kt
+
+import java.util.Arrays
+
+fun box(): S {
+    val l: LS = Arrays.asList("OK")
+    return l[0]
+}