This is an editorial change in the ECMA-262 spec, with similar changes in some proposals. See: - https://github.com/tc39/ecma262/commit/7575f74 - https://github.com/tc39/proposal-array-grouping/commit/df899eb - https://github.com/tc39/proposal-shadowrealm/commit/9eb5a12 - https://github.com/tc39/proposal-shadowrealm/commit/c81f527