Issue #14874: Restore charmap decoding speed to pre-PEP 393 levels.
Patch by Serhiy Storchaka.
diff --git a/Lib/encodings/iso8859_1.py b/Lib/encodings/iso8859_1.py
index 8cfc01f..d9cc516 100644
--- a/Lib/encodings/iso8859_1.py
+++ b/Lib/encodings/iso8859_1.py
@@ -301,6 +301,7 @@
'\xfd' # 0xFD -> LATIN SMALL LETTER Y WITH ACUTE
'\xfe' # 0xFE -> LATIN SMALL LETTER THORN (Icelandic)
'\xff' # 0xFF -> LATIN SMALL LETTER Y WITH DIAERESIS
+ '\ufffe' ## Widen to UCS2 for optimization
)
### Encoding table