regression: no emojis in lifetime names (despite no emojis being present?)

[Mark-Simulacrum]

• https://crater-reports.s3.amazonaws.com/beta-1.69-3/beta-2023-03-18/reg/solores-0.1.2/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.69-3/beta-2023-03-18/reg/tuix_derive-0.2.0/log.txt

Not clear what the cause here is, but worth figuring out.

[ehuss]

Bisected to #108031. cc @jieyouxu / @estebank

[ehuss]

BTW, here's a minimal repro:

macro_rules! foo {
    ($tt1:tt) => {};
}

fn x() {
    foo!('me#foo);
}

[estebank]

Thanks for the ping! Fixing it in #109754. (is_emoji counterintuitively considers # as an emoji.)