Moves the bulk of the business logic for type analyzing await
expressions from the analyzer and front_end codebases into the shared
`TypeAnalyzer` class. There is no functional change.
This paves the way for fixing
https://github.com/dart-lang/sdk/issues/62889 (Unsound type promotion
in inner async/generator functions), which will require the type
analysis of await expressions to be integrated more closely with flow
analysis. Sharing the type analysis logic will avoid the need to do
that integration twice.
Change-Id: I9f8770ce8127a960b746a89ee3e370ed6a6a6964
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/489480
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
Paul Berry
1b1c5d55dc