fixup! rustc_parser: consider the in 2024 an expression

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>

Author: vincenzopalazzo

compiler/rustc_parse/src/parser/nonterminal.rs

@@ -44,8 +44,6 @@ impl<'a> Parser<'a> {
                 && !token.is_keyword(kw::Let)
                 // This exception is here for backwards compatibility.
                 && !token.is_keyword(kw::Const)
-                // FIXME(vincenzopalazzo): query less time the edition
-                && (token.span.edition().at_least_rust_2024() && !token.is_keyword(kw::Underscore) )
             }
             NonterminalKind::Expr(Expr) => {
                 token.can_begin_expr()

tests/ui/macros/expr_2024_underscore_expr.edi2021.stderr

@@ -1,5 +1,5 @@
 error: no rules expected the token `_`
-  --> $DIR/expr_2024_underscore_expr.rs:23:12
+  --> $DIR/expr_2024_underscore_expr.rs:22:12
    |
 LL | macro_rules! m2021 {
    | ------------------ when calling this macro
@@ -8,13 +8,13 @@ LL |     m2021!(_);
    |            ^ no rules expected this token in macro call
    |
 note: while trying to match meta-variable `$e:expr_2021`
-  --> $DIR/expr_2024_underscore_expr.rs:11:6
+  --> $DIR/expr_2024_underscore_expr.rs:10:6
    |
 LL |     ($e:expr_2021) => {
    |      ^^^^^^^^^^^^
 
 error: no rules expected the token `_`
-  --> $DIR/expr_2024_underscore_expr.rs:24:12
+  --> $DIR/expr_2024_underscore_expr.rs:23:12
    |
 LL | macro_rules! m2024 {
    | ------------------ when calling this macro
@@ -23,7 +23,7 @@ LL |     m2024!(_);
    |            ^ no rules expected this token in macro call
    |
 note: while trying to match meta-variable `$e:expr`
-  --> $DIR/expr_2024_underscore_expr.rs:17:6
+  --> $DIR/expr_2024_underscore_expr.rs:16:6
    |
 LL |     ($e:expr) => {
    |      ^^^^^^^