[clang-tools-extra] [clangd] Fix crash when server shuts down with in-flight rename or tweak (PR #198019)

[Aleksandr Platonov via cfe-commits]

https://github.com/ArcsinX commented:

I tried your test without the changes in ClangdLSPServer.cpp and for me the test passes. I tried with debug build and also tried to add some delays inside rename without any success to fail the test. Is it expected?

https://github.com/llvm/llvm-project/pull/198019