This would clean up some of the jtreg tests (in particular in JFR tests, but also potentially other spots) where there is no canonical ordering of @requires which can lead to messy and sometimes redundant entries in some cases. It'll also make merges cleaner from project workspaces.

I'll look to see if specific jcheck:s can flag and enforce a canonical ordering.

Part of it will involve agreeing what a desirable canonical order might be an whether jcheck is the right way to keep it in order.

See https://github.com/openjdk/lilliput/pull/205#issuecomment-3499583520