This is an editorial change in the Intl spec. See:
https://github.com/tc39/ecma402/commit/087995chttps://github.com/tc39/ecma402/commit/233d29c
This also adds a missing spec link for the sanctioned units and fixes a
broken spec link for IsSanctionedSingleUnitIdentifier. In LibUnicode,
the NumberFormat generator is updated to use the constexpr helper to
retrieve sanctioned units.