Refactor use of typeofEquals and instanceof and remove isInstanceOfDomType

[srujzs]

dart:js_interop will have the following changes with https://dart-review.googlesource.com/c/sdk/+/326691:

• typeofEquals takes a String and returns bool
• instanceof returns a bool
• instanceOfString is added to check instanceof with types that are available in the global context. isInstanceOfDomType does the same thing and can be removed.

This will require publishing a new version and updating the minimum SDK.

[kevmoo]

Are the changes to dart:js_interop breaking? Do we have the changelog updated?

[srujzs]

Yes, and yes in the above CL once it lands. It makes sense to have these go in before 3.2 releases before more packages migrate.