Stop considering _ as a keyword

Author: GuillaumeGomez

src/librustdoc/html/highlight.rs

@@ -15,7 +15,7 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_lexer::{Cursor, FrontmatterAllowed, LiteralKind, TokenKind};
 use rustc_span::BytePos;
 use rustc_span::edition::Edition;
-use rustc_span::symbol::Symbol;
+use rustc_span::symbol::{Symbol, kw};
 
 use super::format;
 use crate::clean::PrimitiveType;
@@ -1333,7 +1333,7 @@ impl<'src> Classifier<'src> {
 
 fn is_keyword(symbol: Symbol) -> bool {
     // FIXME(#148221): Don't hard-code the edition. The classifier should take it as an argument.
-    symbol.is_reserved(|| Edition::Edition2024)
+    symbol != kw::Underscore && symbol.is_reserved(|| Edition::Edition2024)
 }
 
 fn generate_link_to_def(