Fix missed error case

Author: dylni

src/windows/mod.rs

@@ -126,6 +126,7 @@ mod tests {
         test_error(End(), b"\xF1\x80");
         test_error(End(), b"\xF1\x80\x80");
         test_error(Byte(b'\xF1'), b"\xF1\x80\x80\xF1");
+        test_error(CodePoint(0x11_09CC), b"\xF4\x90\xA7\x8C");
         test_error(CodePoint(0x15_EC46), b"\xF5\x9E\xB1\x86");
         test_error(End(), b"\xFB");
         test_error(End(), b"\xFB\x80");

src/windows/wtf8/code_points.rs

@@ -80,7 +80,7 @@ where
                 r#continue!();
 
                 if byte >= 0xF0 {
-                    if code_point.wrapping_sub(0x10) > 0x100 {
+                    if code_point.wrapping_sub(0x10) >= 0x100 {
                         invalid = true;
                     }
                     r#continue!();