Should [[RelevantExtensionKeys]] be pre-alphabetized?

[rkirsling]

If UTS 35 expects a canonical locale identifier to have its extensions alphabetized, should we update the [[RelevantExtensionKeys]] lists for Collator and DateTimeFormat to have kf before kn and hc before nu, respectively?

There's no alphabetization to do if the list is already in order, and I don't believe this has any impact on the initialization of either class, since we access the options by name.

[littledan]

@rkirsling It sounds like this would be an editorial change, right? If so, I'm in favor of it.