Be less synchronous

[cgay]

For later...let's be a little less synchronous.

https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#messageOrdering

Especially since compilation can take a while, we could have two work queues: one for tasks that we know do not depend on ordering (e.g., symbol completion) and one for tasks that may depend on ordering (e.g., textDocument/didSave).

[cgay]

Because our linking stage is very slow I turned off linking in the LSP server a while back. But this leaves the user to manually rebuild executables, and when they do it does a full rebuild because (I believe) the build done by dylan-lsp-server is considered incompatible with a build done manually with dylan-compiler. And a full rebuild can be very slow, for example building dylan-lsp-server itself takes minutes.

I don't see any messages in LSP that could be used to trigger a build explicitly that we could use to signal "hey, link it this time please", so my current thinking is that "be less synchronous" is the answer. We can turn on linking again and make the build asynchronous. We can send $/progress messages, hooked up to the progress-callback: of od/build-project.

[cgay]

Following up on previous comment, OPEN_DYLAN_MAJOR_MINOR_CHECKS_ONLY=1 avoids a lot of that recompilation effort. Perhaps we can set this in environment of dylan-lsp-server, or at least document it as a useful lsp-dylan dev setting.