web-feature classification for additional Iterator and Map features

[ChrisC]

This PR maps tests for the following newer web features:

• Iterator.concat()
• getOrInsert (which covers both Map and WeakMap)

cc @jugglinmike for review

[ChrisC]

Noting that we'll have less tests mapped to weakmap as of this change to avoid overlap, so it's expected that the coverage checker will throw a warning. Theses tests are now mapped to the getorinsert feature, so there's no overall reduction in test-to-feature coverage.

[jugglinmike]

I think using tags (upsert and iterator-sequencing) might be better here. Not so much for concision (in fact, there's a good argument to be made for the readability of an explicit list of directories) but for flexibility. The two approaches are equivalent today, but if someone adds a cross-cutting test to another directory later, then a tag-based classifier has a better chance of automatically including it. What do you think?

[ChrisC]

I think using tags (upsert and iterator-sequencing) might be better here...

@jugglinmike addressed in 688838b. How does that look?

[jugglinmike]

@ptomato Can you admin-merge this?

(Context: the linter is rejecting this patch because one of matched sets is shrinking. That's intentional. We designed the linter to behave this way in the interest of avoiding unintentional regression and also to limit its complexity. That design assumes that admins can merge despite failure, though, and Test262 isn't currently configured that way--not for me, anyway. I'm also unable to push the commit to main from my local repository.)

[jugglinmike]

Thanks!