This is a reland of 6a1c54ec30
Original change's description:
> Flow analysis: promote to non-nullable on initialization
>
> When flow analysis encounters a variable declaration of the form `T? x
> = expr;`, if the type of `expr` is `T`, then the variable is
> immediately promoted to type `T`.
>
> Fixes#43099.
>
> Change-Id: Ia206fe0d50e2fdd9bdf637e13c85633d8490dbcc
> Bug: https://github.com/dart-lang/sdk/issues/43099
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/163841
> Commit-Queue: Paul Berry <paulberry@google.com>
> Reviewed-by: Bob Nystrom <rnystrom@google.com>
> Reviewed-by: Johnni Winther <johnniwinther@google.com>
> Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Bug: https://github.com/dart-lang/sdk/issues/43099
Change-Id: I7530bb0f7c24674a7b500558b89d50b35e045aca
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/166305
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>
When flow analysis encounters a variable declaration of the form `T? x
= expr;`, if the type of `expr` is `T`, then the variable is
immediately promoted to type `T`.
Fixes#43099.
Change-Id: Ia206fe0d50e2fdd9bdf637e13c85633d8490dbcc
Bug: https://github.com/dart-lang/sdk/issues/43099
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/163841
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Change-Id: I59ae5b01c00f3bebda0ba74eb5eb1950ade59925
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/137720
Reviewed-by: Erik Ernst <eernst@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>
Auto-Submit: Bob Nystrom <rnystrom@google.com>