bfa78614c8
For `mjs_attachFrame` and `mjs_attachBody`, require either a prefix or suffix. It is tempting for users to not use a prefix (see #2162), but this causes issues. For example, it creates a duplicate "main" default class in the parent as a child of the already existing "main" default. PiperOrigin-RevId: 688535755 Change-Id: I653181ca35943f1e4eb89c70fca8b5289818324e