tree aec2b22cfd2415ba94a20e2ec0021f334dd414e7
parent a8b6e18b6224e7d65caedd80478861f52568de67
author Paul Berry <paulberry@google.com> 1557254097 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> 1557254097 +0000

Rework some migration tests to make use of the nullability graph.

This required tracking the map from a node to the nodes that are
upstream from it.

Change-Id: I079fac2196f3928b521b0866fd6f1790e6f24573
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/101489
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>