Optimize `TokenKind::clone`. `TokenKind` would impl `Copy` if it weren't for `TokenKind::Interpolated`. This commit makes `clone` reflect that. r? `@ghost`
TokenTree::uninterpolate
&self
Cow
cfg
uninlined_format_args
#[main]
#[rustc_main]
become
TokenKind::clone
Iterator
TokenTreeCursor