Tests for analyzer_cli and --summary-deps-output results.

I was not able to find any existing tests, and it looks like an
important feature, which we don't want to break. I will need to verify
that it continues for work with summary2.

[email protected], [email protected]

Change-Id: Ied2985ebd7b71e85a4b49ec43bf22360fbdd01cd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/110126
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>