Biblio file gives precedence to Annex-B productions

[bakkot]

I'm told, though I haven't confirmed this, that a proposal which references a production such as ObjectLiteral which is redefined in Annex B, the proposal will link to the Annex B version instead of the main spec.

I suspect this is because the biblio file lists linkable parts of the spec in order, and annex B gives new definitions to some parts of the grammar, which causes a new entry for the LHS in the biblio file with the same key as the original.

[bakkot]

Fixed by #405.