editor: Improve performance of update_visible_edit_prediction (#44161)

One half of https://github.com/zed-industries/zed/issues/42861

This basically reduces the main thread work for large enough json (and
other) files from multiple milliseconds (15ms was observed in that test
case) down to microseconds (100ms here).

Release Notes:

- Improved cursor movement performance when edit predictions are enabled

crates/editor/src/editor.rs

@@ -182,7 +182,7 @@ use std::{
     iter::{self, Peekable},
     mem,
     num::NonZeroU32,
-    ops::{Deref, DerefMut, Not, Range, RangeInclusive},
+    ops::{ControlFlow, Deref, DerefMut, Not, Range, RangeInclusive},
     path::{Path, PathBuf},
     rc::Rc,
     sync::Arc,
@@ -8073,10 +8073,17 @@ impl Editor {
 
         if self.edit_prediction_indent_conflict {
             let cursor_point = cursor.to_point(&multibuffer);
+            let mut suggested_indent = None;
+            multibuffer.suggested_indents_callback(
+                cursor_point.row..cursor_point.row + 1,
+                |_, indent| {
+                    suggested_indent = Some(indent);
+                    ControlFlow::Break(())
+                },
+                cx,
+            );
 
-            let indents = multibuffer.suggested_indents(cursor_point.row..cursor_point.row + 1, cx);
-
-            if let Some((_, indent)) = indents.iter().next()
+            if let Some(indent) = suggested_indent
                 && indent.len == cursor_point.column
             {
                 self.edit_prediction_indent_conflict = false;