Adds a generator that reads the platform libraries dill and outputs
maps that correspond to the various bindings e.g. `@Native` values
that exist in the web libraries. These maps will be consumed during
the analyzer run for lints.
Change-Id: I5b5bf91ff0e32964b97c9e52be414ec84ff88765
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/272720
Commit-Queue: Srujan Gaddam <srujzs@google.com>
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Riley Porter <rileyporter@google.com>
