Fix `fmt::Debug` for strings, e.g. for Chinese characters

The problem occured due to lines like

```
3400;<CJK Ideograph Extension A, First>;Lo;0;L;;;;;N;;;;;
4DB5;<CJK Ideograph Extension A, Last>;Lo;0;L;;;;;N;;;;;
```

in `UnicodeData.txt`, which the script previously interpreted as two
characters, although it represents the whole range.

Fixes #34318.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/libcoretest/char.rs b/src/libcoretest/char.rs
index 7da0b6902f2..b4088ffbf89 100644
--- a/src/libcoretest/char.rs
+++ b/src/libcoretest/char.rs
@@ -162,6 +162,8 @@ fn test_escape_debug() {
     assert_eq!(s, "~");
     let s = string('é');
     assert_eq!(s, "é");
+    let s = string('文');
+    assert_eq!(s, "文");
     let s = string('\x00');
     assert_eq!(s, "\\u{0}");
     let s = string('\x1f');