bundlerepo: don't insert index tuples with full nodes as linkrev The index format has a documented format and latter changes will start to enforce the field types. The bundlerepo uses full nodes for the linkrev field when it should be using revision numbers. Use the link mapping to resolve them, except in the special case of self-references. Those are actually indications of a missing linkrev. Differential Revision: https://phab.mercurial-scm.org/D9160