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_hir_pretty/src/lib.rs

@@ -1247,7 +1247,7 @@ impl<'a> State<'a> {
 
     fn print_literal(&mut self, lit: &hir::Lit) {
         self.maybe_print_comment(lit.span.lo());
-        self.word(lit.node.to_lit_token().to_string())
+        self.word(lit.node.to_token_lit().to_string())
     }
 
     fn print_inline_asm(&mut self, asm: &hir::InlineAsm<'_>) {