CWG3106 [lex.universal.char] Redundant exclusion of (non-existent) UCNs in r-char-sequences

[hubert-reinterpretcast]

Full name of submitter (unless configured in github; will be published with the issue): Hubert Tong

Reference (section label): [lex.universal.char]

Link to reflector thread (if any): N/A

Issue description:

https://wg21.link/lex.universal.char#1.sentence-2 specifically excludes UCNs within r-char-sequence‌s but such UCNs do not exist anyway (as the note that immediately follows points out).

Suggested resolution:

Edit in [lex.universal.char] paragraph 1:

[ ... ] If a universal-character-name outside the c-char-sequence, or s-char-sequence, or r-char-sequence of [ ... ]

[jensmaurer]

CWG3106