Remove `MacDelimiter`.

It's the same as `Delimiter`, minus the `Invisible` variant. I'm
generally in favour of using types to make impossible states
unrepresentable, but this one feels very low-value, and the conversions
between the two types are annoying and confusing.

Look at the change in `src/tools/rustfmt/src/expr.rs` for an example:
the old code converted from `MacDelimiter` to `Delimiter` and back
again, for no good reason. This suggests the author was confused about
the types.

1 files changed, 3 insertions, 2 deletions

diff --git a/compiler/rustc_builtin_macros/src/assert.rs b/compiler/rustc_builtin_macros/src/assert.rs
index ab4ea9c8c20..3e90ae6907f 100644
--- a/compiler/rustc_builtin_macros/src/assert.rs
+++ b/compiler/rustc_builtin_macros/src/assert.rs
@@ -4,8 +4,9 @@ use crate::edition_panic::use_panic_2021;
 use crate::errors;
 use rustc_ast::ptr::P;
 use rustc_ast::token;
+use rustc_ast::token::Delimiter;
 use rustc_ast::tokenstream::{DelimSpan, TokenStream};
-use rustc_ast::{DelimArgs, Expr, ExprKind, MacCall, MacDelimiter, Path, PathSegment, UnOp};
+use rustc_ast::{DelimArgs, Expr, ExprKind, MacCall, Path, PathSegment, UnOp};
 use rustc_ast_pretty::pprust;
 use rustc_errors::PResult;
 use rustc_expand::base::{DummyResult, ExtCtxt, MacEager, MacResult};
@@ -58,7 +59,7 @@ pub fn expand_assert<'cx>(
                 path: panic_path(),
                 args: P(DelimArgs {
                     dspan: DelimSpan::from_single(call_site_span),
-                    delim: MacDelimiter::Parenthesis,
+                    delim: Delimiter::Parenthesis,
                     tokens,
                 }),
             })),