Update or remove obsolete articles

[kwalrath]

• [x] https://www.dartlang.org/articles/language
  • [ ] https://www.dartlang.org/articles/language/await-async - #512 suggests combining async/generator docs.
  • [ ] https://www.dartlang.org/articles/language/beyond-async - #512 suggests combining async/generator docs.
  • [x] https://www.dartlang.org/articles/language/emulating-functions - #600 has a list of changes to make.
  • [x] https://www.dartlang.org/articles/language/mixins [UPDATED: #978]
• [ ] https://www.dartlang.org/articles/libraries
  • [ ] https://www.dartlang.org/articles/libraries/broadcast-streams
  • [ ] https://www.dartlang.org/articles/libraries/converters-and-codecs
  • [x] https://www.dartlang.org/articles/libraries/creating-streams - PR: #1180
  • [x] https://www.dartlang.org/articles/libraries/serialization - PRs: #253, #1034
  • [ ] https://www.dartlang.org/articles/libraries/zones - issues: #2151, #2150, #2149, #2148, #2147
• [ ] https://www.dartlang.org/articles/server - The path used to be /articles/dart-vm. To see the pre-move history, look at a pre-move source tree.)
  • [x] https://www.dartlang.org/articles/server/benchmarking - PR: #1034
  • [x] https://www.dartlang.org/articles/server/io - #275 - PR: #1110
  • [x] https://www.dartlang.org/articles/server/native-extensions - was blocked on https://dart-review.googlesource.com/c/sdk/+/63260; in May, Siva said no updates seemed to be needed.
  • [x] https://www.dartlang.org/articles/dart-vm/numeric-computation - PR: #1034
  • [x] https://www.dartlang.org/articles/dart-vm/reflection-with-mirrors - #32; don't plan to update, since mirrors aren't recommended in most cases.
  • [x] https://www.dartlang.org/articles/dart-vm/simd - PR: #1034

[kwalrath]

Per the discussion on dart-lang/sdk#33960, here's my proposal:

I get each article reviewed by the most knowledgable people I can find on the subject, and then add a note at the top of each article that addresses the following points:

• Who should read (or not read) the article, and why (or why not).
• What's changed since the article was written.
• What's still true.
• What's important.
• Where else they can find information on this topic.

For articles that have important content, we should consider either updating the article or writing more maintainable documentation somewhere — perhaps in the dart-lang/sdk repo, where engineers working on the source code are more likely to encounter and update it.

[atsansone]

This list of links applied to prior infrastructure. The degree of changes make this issue obsolete. If this is still a going concern, please create a new issue and update relevant information. Thanks!