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_lint/src/hidden_unicode_codepoints.rs

@@ -120,8 +120,8 @@ impl EarlyLintPass for HiddenUnicodeCodepoints {
     fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &ast::Expr) {
         // byte strings are already handled well enough by `EscapeError::NonAsciiCharInByteString`
         let (text, span, padding) = match &expr.kind {
-            ast::ExprKind::Lit(ast::Lit { token, kind, span }) => {
-                let text = token.symbol;
+            ast::ExprKind::Lit(ast::Lit { token_lit, kind, span }) => {
+                let text = token_lit.symbol;
                 if !contains_text_flow_control_chars(text.as_str()) {
                     return;
                 }