LSP document highlight handler broken on latest Neovim master

[jose-elias-alvarez]

Describe the bug handle_document_highlight hasn't been adapted for neovim/neovim#15504, so the LSP highlighting functionality from vim-illuminate doesn't work on the latest Neovim master.

To Reproduce

1. Build Neovim from the latest master
2. Enable the LSP integration for any language server, as described in the readme
3. Open a file and wait for LSP attach
4. Hover over a variable

Expected behavior References get highlighted and moving between references with next_referenceworks.

Additional context For reference, the following diff fixes the issue while maintaining compatibility with the old handler signature (I didn't put in a PR, since this is just one of many ways to solve the issue):

diff --git a/lua/illuminate.lua b/lua/illuminate.lua
index f4a0b20..8ec81fa 100644
--- a/lua/illuminate.lua
+++ b/lua/illuminate.lua
@@ -51,7 +51,26 @@ local function cursor_in_references(bufnr)
     return false
 end

-local function handle_document_highlight(_, _, result, _, bufnr, _) -- TODO use client_id
+local function make_handler(fn)
+    return function(...)
+        local config_or_client_id = select(4, ...)
+        local is_new = type(config_or_client_id) ~= 'number'
+        if is_new then
+            fn(...)
+        else
+            local err = select(1, ...)
+            local method = select(2, ...)
+            local result = select(3, ...)
+            local client_id = select(4, ...)
+            local bufnr = select(5, ...)
+            local config = select(6, ...)
+            fn(err, result, { method = method, client_id = client_id, bufnr = bufnr }, config)
+        end
+    end
+end
+
+local handle_document_highlight = make_handler(function(_, result, ctx) -- TODO use client_id
+    bufnr = ctx.bufnr
     if not bufnr then return end
     local btimer = timers[bufnr]
     if btimer then
@@ -71,7 +90,7 @@ local function handle_document_highlight(_, _, result, _, bufnr, _) -- TODO use
         return before_by_start(a.range, b.range)
     end)
     references[bufnr] = result
-end
+end)

 local function valid(bufnr, range)
     return range