This PR adds a new command to the Carbon VSCode extension "carbon:
Restart language server" which acts similar to clangd / bazel
extensions. While not useful during regular working of the extension
this helps when LSP either crashes or the toolchain is updated.
In order to support graceful restart, I needed to add a Call handler for
"shutdown" which is noop for now. Lsp clients always call shutdown
before sending exit.
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Co-authored-by: jonmeow <jperkins@google.com>
Add caching of parsed documents, and testing of the textDocument
handlers. This is based on #4896, which splits out some of the
boilerplate to calls.
Note, this caches the entire parse state because we'll want to try to
emit diagnostics when we see the update, without waiting. It may be
helpful to do that asynchronously, but we don't want to wait for another
call (such as documentSymbol). Really, we'll probably want to also add
check for diagnostics, at least.
DavidLoftusandjonmeow