This makes sure we can distinguish e.g. 2 different timeline.dart files
(from runtime/lib/timeline.dart and sdk/lib/developer/timeline.dart)
This CL also fixes the owner of constructors to be patch classes, if
the constructors come from a patch.
This CL also adds a service/valid_source_locations_test, which loops
over libraries/classes/fields/functions and obtains source locations for
them, including line numbers. This ensures that if there is a source
location attached to a member, we can use it's token position to get to
the line number.
This CL also changes package:kernel's [Cloner] to clone fileOffsets (and
not just fileEndOffsets). This is important for mixin resolution, where
we copy members into mixin application classes.
Issue https://github.com/dart-lang/sdk/issues/32489
Change-Id: I4fea5cd646d81f47e1c4ede1e86d477ba6de3e82
Reviewed-on: https://dart-review.googlesource.com/46141
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>