Rename some things related to literals.

- Rename `ast::Lit::token` as `ast::Lit::token_lit`, because its type is
  `token::Lit`, which is not a token. (This has been confusing me for a
  long time.)
  reasonable because we have an `ast::token::Lit` inside an `ast::Lit`.
- Rename `LitKind::{from,to}_lit_token` as
  `LitKind::{from,to}_token_lit`, to match the above change and
  `token::Lit`.

compiler/rustc_expand/src/proc_macro_server.rs

@@ -486,20 +486,26 @@ impl server::TokenStream for Rustc<'_, '_> {
         // We don't use `TokenStream::from_ast` as the tokenstream currently cannot
         // be recovered in the general case.
         match &expr.kind {
-            ast::ExprKind::Lit(l) if l.token.kind == token::Bool => Ok(
-                tokenstream::TokenStream::token_alone(token::Ident(l.token.symbol, false), l.span),
-            ),
+            ast::ExprKind::Lit(l) if l.token_lit.kind == token::Bool => {
+                Ok(tokenstream::TokenStream::token_alone(
+                    token::Ident(l.token_lit.symbol, false),
+                    l.span,
+                ))
+            }
             ast::ExprKind::Lit(l) => {
-                Ok(tokenstream::TokenStream::token_alone(token::Literal(l.token), l.span))
+                Ok(tokenstream::TokenStream::token_alone(token::Literal(l.token_lit), l.span))
             }
             ast::ExprKind::Unary(ast::UnOp::Neg, e) => match &e.kind {
-                ast::ExprKind::Lit(l) => match l.token {
+                ast::ExprKind::Lit(l) => match l.token_lit {
                     token::Lit { kind: token::Integer | token::Float, .. } => {
                         Ok(Self::TokenStream::from_iter([
                             // FIXME: The span of the `-` token is lost when
                             // parsing, so we cannot faithfully recover it here.
                             tokenstream::TokenTree::token_alone(token::BinOp(token::Minus), e.span),
-                            tokenstream::TokenTree::token_alone(token::Literal(l.token), l.span),
+                            tokenstream::TokenTree::token_alone(
+                                token::Literal(l.token_lit),
+                                l.span,
+                            ),
                         ]))
                     }
                     _ => Err(()),