This allows us to clean up the creation of `TestBuildSystem` a little bit because the tests can create `TestBuildSystem` instead of retrieving it from the `BuildSystemManager`.
rdar://142906050
(cherry picked from commit 31b1909ce1)
When we receive build settings after hitting the timeout, we call `fileBuildSettingsChanged` on the delegate, which should cause the document to get re-opened in sourcekitd and diagnostics to get refreshed.
rdar://136332685
Fixes#1693
When we receive build settings after hitting the timeout, we call `fileBuildSettingsChanged` on the delegate, which should cause the document to get re-opened in sourcekitd and diagnostics to get refreshed.
rdar://136332685
