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.
I'm trying to make the LSP look more like the rest of the toolchain. I'm
trying to separate the handlers from the transport layer, and remove the
multiple inheritance aspect. Also fixing some style issues, switching to
`Map`, and removing an unnecessary copt.
I'm using `Context` for the central object for consistency with other
portions of the toolchain. In order to get the `handle_*` files working,
I'm using LLVM's registry class. It has a quirk that I can't register
two registries in the same cpp file, so there are two one-line cpp
files.
In order to help show the delta (or lack thereof) for actual
implementation, I've copied server.cpp over handle_* and undone that in
two commits. See the third and fourth commits on the PR history for
that.
Jon Ross-Perkins