Rollup merge of #144657 - Muscraft:fix-unicode-close-window, r=fee1-dead

fix: Only "close the window" when its the last annotated file

While comparing the Unicode theme output of `rustc` and `annotate-snippets`, I found that `rustc` would ["close the window"](https://github.com/rust-lang/rust/blob/686bc1c5f9c06762b18082434c04d514acf6707e/compiler/rustc_errors/src/emitter.rs#L1025-L1027) (draw a `╰╴`), even though there were other annotated files that followed the current one. This PR makes it so the emitter will only "close the window" on the last annotated file.

Before:
```
error[E0624]: method `method` is private
   ╭▸ $DIR/close_window.rs:9:7
   │
LL │     s.method();
   ╰╴      ━━━━━━ private method
   │
   ⸬ $DIR/auxiliary/close_window.rs:3:5
   │
LL │     fn method(&self) {}
   ╰╴    ──────────────── private method defined here
```

After:
```
error[E0624]: method `method` is private
   ╭▸ $DIR/close_window.rs:9:7
   │
LL │     s.method();
   │       ━━━━━━ private method
   │
   ⸬ $DIR/auxiliary/close_window.rs:3:5
   │
LL │     fn method(&self) {}
   ╰╴    ──────────────── private method defined here
```

1 files changed, 5 insertions, 2 deletions

diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 46a4a186824..3fe525df94f 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -1597,8 +1597,9 @@ impl HumanEmitter {
             annotated_files.swap(0, pos);
         }
 
+        let annotated_files_len = annotated_files.len();
         // Print out the annotate source lines that correspond with the error
-        for annotated_file in annotated_files {
+        for (file_idx, annotated_file) in annotated_files.into_iter().enumerate() {
             // we can't annotate anything if the source is unavailable.
             if !should_show_source_code(
                 &self.ignored_directories_in_source_blocks,
@@ -1855,7 +1856,9 @@ impl HumanEmitter {
                         width_offset,
                         code_offset,
                         margin,
-                        !is_cont && line_idx + 1 == annotated_file.lines.len(),
+                        !is_cont
+                            && file_idx + 1 == annotated_files_len
+                            && line_idx + 1 == annotated_file.lines.len(),
                     );
 
                     let mut to_add = FxHashMap::default();