[clang-tools-extra] [llvm] [clangd] Outline LSP payload decode errors (PR #203121)

[Aleksandr Platonov via cfe-commits]

https://github.com/ArcsinX requested changes to this pull request.

We have the same pattern here https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/Support/LSP/Transport.h#L171

I think if we decide to commit this, we need to fix it in two places using a single function that creates an `LSPError` (and use this function in both places).
BTW, the name `parseError` isn't quite right, since we aren't parsing an error, but handling it.

https://github.com/llvm/llvm-project/pull/203121