cb96256bc2
Replace index / search of `CompilationUnitElement` with special `referencesLibraryFragment(LibraryFragment)`, because they are not elements. Change-Id: I4de4ce42270bdad92996bedbd06f108a7c71dffe Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/412681 Reviewed-by: Paul Berry <paulberry@google.com> Commit-Queue: Konstantin Shcheglov <scheglov@google.com>