In so-called "object short notation," an IdentifierName is interpreted as both a LiteralPropertyName and an IdentifierReference. The second is a more restrictive goal than the first, so it is not necessary to apply the LiteralPropertyName validation rules. Removing that validation logic allows for an otherwise-unused parameter of the internal `propertyName` function to be removed.
We've landed a bunch of bug fixes to the
I've pushed the prior version of this branch to my fork of the repository in case that's helpful.