[clang-tools-extra] Add --project-root to clangd (PR #155905)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

Ah, I see, so it's actually a UBSan error, and it's complaining at the read of `ClangdServer::Options::StrongWorkspaceMode` in `ClangdLSPServer::onInitialize()` that we're reading a value of 49 from a bool, which suggests that bool was not initialized.

Should be a simple fix, just need to give this field a class member initializer.

@Dominicentek heads up that this has been reverted and you'll need to resubmit with this fix to move forward with this change

https://github.com/llvm/llvm-project/pull/155905