perf: use vim.lsp.util.get_line to get line instad of bufload

lua/trouble/util.lua

@@ -70,11 +70,21 @@ M.severity = {
 
 function M.process_item(item, bufnr)
   local filename = vim.api.nvim_buf_get_name(bufnr)
+  local uri = vim.uri_from_bufnr(bufnr)
   local start = item.range["start"]
   local finish = item.range["end"]
   local row = start.line
   local col = start.character
-  local line = (vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false) or { "" })[1]
+
+  local line
+  if vim.lsp.util.get_line then
+    line = vim.lsp.util.get_line(uri, row)
+  else
+    -- load the buffer when needed
+    vim.fn.bufload(bufnr)
+    line = (vim.api.nvim_buf_get_lines(bufnr, row, row + 1, false) or { "" })[1]
+  end
+
   item.message = item.message or line or ""
 
   ---@class Item
@@ -112,8 +122,6 @@ function M.locations_to_items(results, default_severity)
       if not vim.tbl_isempty(loc) then
         local buf = loc.uri and vim.uri_to_bufnr(loc.uri) or bufnr
         loc.severity = loc.severity or default_severity
-        -- load the buffer when needed
-        vim.fn.bufload(buf)
         table.insert(ret, M.process_item(loc, buf))
       end
     end