Add a new function to redraw diagnostics from the current diagnostic
cache, without receiving a "publishDiagnostics" message from the server.
This is already being done in two places in the Lua stdlib, so this
function unifies that functionality in addition to providing it to third
party plugins.
An example use case for this could be a command or key-binding for
toggling diagnostics virtual text. The virtual text configuration option
can be toggled using `vim.lsp.with` followed by
`vim.lsp.diagnostic.redraw()` to immediately redraw the diagnostics
with the updated setting.
Remove syncolor.vim in favor of defining the default highlight groups
directly in `init_highlight`. This approach provides a number of
advantages:
1. The highlights are always defined, regardless of whether or not the
syntax regex engine is enabled.
2. Redundant sourcing of syntax files is eliminated (syncolor.vim was
often sourced multiple times based on how the user's colorscheme file
was written).
3. The syntax highlighting regex engine and the highlight groups
themselves are more fully decoupled.
4. Removal of the confusing `:syntax on` / `:syntax enable` dichotomy
(they now both do the same thing).
This approach also correctly solves a number of bugs related to
highlighting (#15176, #12573, #15205).
The handlers for textDocument/references, textDocument/documentSymbol,
and workspace/symbol open their results in the quickfix list by default
and are not configurable. They are also incompatible with `vim.lsp.with`
as they do not accept a configuration parameter.
Add a `config` parameter to the handler for these three messages which
allows them to be configured with `vim.lsp.with`. Additionally, add a
new configuration option 'loclist' that, when true, causes these
handlers to open their results in the location list rather than the
quickfix list.
This fixes an issue introduced in #14771 (fix: source syncolors.vim
before startup scripts) that affected highlights for users who set
'background' to light in their startup script. Because syncolor.vim
checks for the value of &background, it was always setting up the 'dark'
background colors, which looked wrong for users using light backgrounds.
The primary benefit of #14771 is that it decoupled highlighting from the
syntax engine. This is useful for e.g. treesitter, which still makes use
of highlights even if the syntax engine is disabled. For this reason, it
is still worthwhile to source syncolor.vim separately from synload.vim,
which #14771 accomplishes. However, we should still source syncolor.vim
after the user startup scripts, to ensure that we are respecting the
options the user sets.
Another corollary benefit is that this reduces some redundancy in
highlight definitions, since we now only source syncolors.vim if the
user did not already enable a colorscheme.
