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.

3 files changed, 9 insertions, 6 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,
                 }),
             })),
diff --git a/compiler/rustc_builtin_macros/src/assert/context.rs b/compiler/rustc_builtin_macros/src/assert/context.rs
index 902c1e40c75..cbf115127cf 100644
--- a/compiler/rustc_builtin_macros/src/assert/context.rs
+++ b/compiler/rustc_builtin_macros/src/assert/context.rs
@@ -1,9 +1,10 @@
 use rustc_ast::{
     ptr::P,
     token,
+    token::Delimiter,
     tokenstream::{DelimSpan, TokenStream, TokenTree},
-    BinOpKind, BorrowKind, DelimArgs, Expr, ExprKind, ItemKind, MacCall, MacDelimiter, MethodCall,
-    Mutability, Path, PathSegment, Stmt, StructRest, UnOp, UseTree, UseTreeKind, DUMMY_NODE_ID,
+    BinOpKind, BorrowKind, DelimArgs, Expr, ExprKind, ItemKind, MacCall, MethodCall, Mutability,
+    Path, PathSegment, Stmt, StructRest, UnOp, UseTree, UseTreeKind, DUMMY_NODE_ID,
 };
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashSet;
@@ -179,7 +180,7 @@ impl<'cx, 'a> Context<'cx, 'a> {
                 path: panic_path,
                 args: P(DelimArgs {
                     dspan: DelimSpan::from_single(self.span),
-                    delim: MacDelimiter::Parenthesis,
+                    delim: Delimiter::Parenthesis,
                     tokens: initial.into_iter().chain(captures).collect::<TokenStream>(),
                 }),
             })),
diff --git a/compiler/rustc_builtin_macros/src/edition_panic.rs b/compiler/rustc_builtin_macros/src/edition_panic.rs
index ef0db23ff2f..1e1dadab480 100644
--- a/compiler/rustc_builtin_macros/src/edition_panic.rs
+++ b/compiler/rustc_builtin_macros/src/edition_panic.rs
@@ -1,4 +1,5 @@
 use rustc_ast::ptr::P;
+use rustc_ast::token::Delimiter;
 use rustc_ast::tokenstream::{DelimSpan, TokenStream};
 use rustc_ast::*;
 use rustc_expand::base::*;
@@ -60,7 +61,7 @@ fn expand<'cx>(
                 },
                 args: P(DelimArgs {
                     dspan: DelimSpan::from_single(sp),
-                    delim: MacDelimiter::Parenthesis,
+                    delim: Delimiter::Parenthesis,
                     tokens: tts,
                 }),
             })),