Handle older parent resources

When an older pulumi/pulumi is used for a parent than that used for a chid resoruce, it was possible for the `__aliases` property to be undefined.

These changes handle that case, and make the recently added private properties of Resource optional to better represent the fact that instances of Resource may not have these values set.

sdk/nodejs/resource.ts

@@ -144,14 +144,14 @@ export abstract class Resource {
      * A list of aliases applied to this resource.
      */
     // tslint:disable-next-line:variable-name
-    readonly __aliases: Input<URN>[];
+    readonly __aliases?: Input<URN>[];
 
     /**
      * @internal
      * The name assigned to the resource at construction.
      */
     // tslint:disable-next-line:variable-name
-    private readonly __name: string;
+    private readonly __name?: string;
 
     /**
      * @internal
@@ -217,8 +217,10 @@ export abstract class Resource {
 
             // Make a copy of the aliases array, and add to it any implicit aliases inherited from its parent
             opts.aliases = [...(opts.aliases || [])];
-            for (const parentAlias of opts.parent.__aliases) {
-                opts.aliases.push(inheritedChildAlias(name, opts.parent.__name, parentAlias, t));
+            for (const parentAlias of (opts.parent.__aliases || [])) {
+                if (opts.parent.__name) {
+                    opts.aliases.push(inheritedChildAlias(name, opts.parent.__name, parentAlias, t));
+                }
             }
 
             this.__providers = opts.parent.__providers;