Remove `token::{Open,Close}Delim`.

By replacing them with `{Open,Close}{Param,Brace,Bracket,Invisible}`.

PR #137902 made `ast::TokenKind` more like `lexer::TokenKind` by
replacing the compound `BinOp{,Eq}(BinOpToken)` variants with fieldless
variants `Plus`, `Minus`, `Star`, etc. This commit does a similar thing
with delimiters. It also makes `ast::TokenKind` more similar to
`parser::TokenType`.

This requires a few new methods:
- `TokenKind::is_{,open_,close_}delim()` replace various kinds of
  pattern matches.
- `Delimiter::as_{open,close}_token_kind` are used to convert
  `Delimiter` values to `TokenKind`.

Despite these additions, it's a net reduction in lines of code. This is
because e.g. `token::OpenParen` is so much shorter than
`token::OpenDelim(Delimiter::Parenthesis)` that many multi-line forms
reduce to single line forms. And many places where the number of lines
doesn't change are still easier to read, just because the names are
shorter, e.g.:
```
-   } else if self.token != token::CloseDelim(Delimiter::Brace) {
+   } else if self.token != token::CloseBrace {
```

1 files changed, 1 insertions, 3 deletions

diff --git a/compiler/rustc_attr_parsing/src/parser.rs b/compiler/rustc_attr_parsing/src/parser.rs
index 384fae59873..40aa39711d3 100644
--- a/compiler/rustc_attr_parsing/src/parser.rs
+++ b/compiler/rustc_attr_parsing/src/parser.rs
@@ -430,9 +430,7 @@ impl<'a> MetaItemListParserContext<'a> {
                 let span = span.with_hi(segments.last().unwrap().span.hi());
                 Some(AttrPath { segments: segments.into_boxed_slice(), span })
             }
-            TokenTree::Token(Token { kind: token::OpenDelim(_) | token::CloseDelim(_), .. }, _) => {
-                None
-            }
+            TokenTree::Token(Token { kind, .. }, _) if kind.is_delim() => None,
             _ => {
                 // malformed attributes can get here. We can't crash, but somewhere else should've
                 // already warned for this.