This gets close to all of the remaining ones.
Updates #12912
Change-Id: I9c672bbed2654a6c5cab31e0cbece6c107d8c6fa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is an exact copy of the files misc/set/set{,_test}.go from
tailscale/corp@a5415daa9c, plus the
license headers.
For use in #7877
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I712d09c6d1a180c6633abe3acf8feb59b27e2866