This doesn't include the copious changes in collection_patch.dart
because I believe (1) those are quite old and (2) are dart2js specific.
The changes here have basically no effect on DDC, but it at least gets
us a little better test coverage and reduces noise in the diffs.
R=sra@google.com
Review URL: https://codereview.chromium.org/1977003002 .
We initially hard coded a few of these. That worked until native_typed_data and html were added. Those two libraries have a lot of native types.
This also fixes TypeRep to extend dart:core Object, and fixes the dart:_runtime so we can write Dart classes. Cleans up a few of the JS builtins as well.
R=vsm@google.com
Review URL: https://codereview.chromium.org/1962823002 .
Bob Nystrom