4e283a7e08
This adds support for an 'include' tag in libraries specifications that enable composite declarations. With this, we can avoid relying on copied portions of (other) specifications. Closes https://github.com/dart-lang/sdk/issues/47998 Change-Id: I694d5c006741e6625feb7cdd5898946cc6caee50 Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/224952 Reviewed-by: Sigmund Cherem <sigmund@google.com>