Also export internalProperty as state (lit#1162)

For future compat

Author: rictic

src/lib/decorators.ts

@@ -482,3 +482,9 @@ export function queryAssignedNodes(
         standardQuery(descriptor, protoOrDescriptor as ClassElement);
   };
 }
+
+
+/**
+ * The future-compatible name for the internalProperty decorator.
+ */
+export const state = internalProperty;