Support .editorconfig (#19455)

Closes https://github.com/zed-industries/zed/issues/8534
Supersedes https://github.com/zed-industries/zed/pull/16349

Potential concerns:
* we do not follow up to the `/` when looking for `.editorconfig`, only
up to the worktree root.
Seems fine for most of the cases, and the rest should be solved
generically later, as the same issue exists for settings.json
* `fn language` in `AllLanguageSettings` is very hot, called very
frequently during rendering. We accumulate and parse all `.editorconfig`
file contents beforehand, but have to go over globs and match these
against the path given + merge the properties still.
This does not seem to be very bad, but needs more testing and
potentially some extra caching.


Release Notes:

- Added .editorconfig support

---------

Co-authored-by: Ulysse Buonomo <buonomo.ulysse@gmail.com>

crates/editor/src/display_map.rs

@@ -423,11 +423,12 @@ impl DisplayMap {
     }
 
     fn tab_size(buffer: &Model<MultiBuffer>, cx: &mut ModelContext<Self>) -> NonZeroU32 {
+        let buffer = buffer.read(cx).as_singleton().map(|buffer| buffer.read(cx));
         let language = buffer
-            .read(cx)
-            .as_singleton()
-            .and_then(|buffer| buffer.read(cx).language());
-        language_settings(language, None, cx).tab_size
+            .and_then(|buffer| buffer.language())
+            .map(|l| l.name());
+        let file = buffer.and_then(|buffer| buffer.file());
+        language_settings(language, file, cx).tab_size
     }
 
     #[cfg(test)]

crates/editor/src/editor.rs

@@ -90,7 +90,7 @@ pub use inline_completion_provider::*;
 pub use items::MAX_TAB_TITLE_LEN;
 use itertools::Itertools;
 use language::{
-    language_settings::{self, all_language_settings, InlayHintSettings},
+    language_settings::{self, all_language_settings, language_settings, InlayHintSettings},
     markdown, point_from_lsp, AutoindentMode, BracketPair, Buffer, Capability, CharKind, CodeLabel,
     CursorShape, Diagnostic, Documentation, IndentKind, IndentSize, Language, OffsetRangeExt,
     Point, Selection, SelectionGoal, TransactionId,
@@ -428,8 +428,7 @@ impl Default for EditorStyle {
 }
 
 pub fn make_inlay_hints_style(cx: &WindowContext) -> HighlightStyle {
-    let show_background = all_language_settings(None, cx)
-        .language(None)
+    let show_background = language_settings::language_settings(None, None, cx)
         .inlay_hints
         .show_background;
 
@@ -4248,7 +4247,10 @@ impl Editor {
             .text_anchor_for_position(position, cx)?;
 
         let settings = language_settings::language_settings(
-            buffer.read(cx).language_at(buffer_position).as_ref(),
+            buffer
+                .read(cx)
+                .language_at(buffer_position)
+                .map(|l| l.name()),
             buffer.read(cx).file(),
             cx,
         );
@@ -13374,11 +13376,8 @@ fn inlay_hint_settings(
     cx: &mut ViewContext<'_, Editor>,
 ) -> InlayHintSettings {
     let file = snapshot.file_at(location);
-    let language = snapshot.language_at(location);
-    let settings = all_language_settings(file, cx);
-    settings
-        .language(language.map(|l| l.name()).as_ref())
-        .inlay_hints
+    let language = snapshot.language_at(location).map(|l| l.name());
+    language_settings(language, file, cx).inlay_hints
 }
 
 fn consume_contiguous_rows(

crates/editor/src/indent_guides.rs

@@ -39,9 +39,13 @@ impl Editor {
     ) -> Option<Vec<MultiBufferIndentGuide>> {
         let show_indent_guides = self.should_show_indent_guides().unwrap_or_else(|| {
             if let Some(buffer) = self.buffer().read(cx).as_singleton() {
-                language_settings(buffer.read(cx).language(), buffer.read(cx).file(), cx)
-                    .indent_guides
-                    .enabled
+                language_settings(
+                    buffer.read(cx).language().map(|l| l.name()),
+                    buffer.read(cx).file(),
+                    cx,
+                )
+                .indent_guides
+                .enabled
             } else {
                 true
             }