the LSP annotator thread is shut down with AsyncShutdown, and frequently isn't shut down by the time a test exits. This switches it to Shutdown(), since that shouldn't add much time (to shut down an idle thread), and I doubt this runs very often (likely once at startup). Perhaps we should instead mark threads in AsyncShutdown such that we wait on finishing the shutdown in the ThreadManager shutdown without asserting.

let me know if you want to instead modify AsyncShutdown (assuming these all were actually in AsyncShutdown, which a Try will verify)

Comment on attachment 8750970 [details] [diff] [review] Shut down LSP Annotator thread synchronously Patch doesn't seem to solve (all) the problems with LSP