EnumDeclaration:
    enum Identifier EnumBody
    enum EnumBody
    enum identifier : EnumBaseType EnumBody
    enum EnumBody : EnumBaseType


Should be:

 EnumDeclaration:
    enum Identifier EnumBody
    enum EnumBody
    enum identifier : EnumBaseType EnumBody
    enum : EnumBaseType EnumBody

Difference in the last line.

Good catch. Thanks.