Streamline token printing functions.

Remove `PrintState::token{,_kind}_to_string`, because they're very thin
wrappers for `PrintState::token{,_kind}_to_string_ext` that obscure more
than they clarify. And rename the latter two methods.

compiler/rustc_ast_pretty/src/pprust/mod.rs

@@ -16,12 +16,12 @@ pub fn nonterminal_to_string(nt: &Nonterminal) -> String {
 
 /// Print the token kind precisely, without converting `$crate` into its respective crate name.
 pub fn token_kind_to_string(tok: &TokenKind) -> Cow<'static, str> {
-    State::new().token_kind_to_string(tok)
+    State::new().token_kind_to_string(tok, None)
 }
 
 /// Print the token precisely, without converting `$crate` into its respective crate name.
 pub fn token_to_string(token: &Token) -> Cow<'static, str> {
-    State::new().token_to_string(token)
+    State::new().token_to_string(token, false)
 }
 
 pub fn ty_to_string(ty: &ast::Ty) -> String {

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -666,7 +666,7 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
     fn print_tt(&mut self, tt: &TokenTree, convert_dollar_crate: bool) -> Spacing {
         match tt {
             TokenTree::Token(token, spacing) => {
-                let token_str = self.token_to_string_ext(token, convert_dollar_crate);
+                let token_str = self.token_to_string(token, convert_dollar_crate);
                 self.word(token_str);
                 if let token::DocComment(..) = token.kind {
                     self.hardbreak()
@@ -770,12 +770,12 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
                 self.bclose(span, empty);
             }
             delim => {
-                let token_str = self.token_kind_to_string(&token::OpenDelim(delim));
+                let token_str = self.token_kind_to_string(&token::OpenDelim(delim), None);
                 self.word(token_str);
                 self.ibox(0);
                 self.print_tts(tts, convert_dollar_crate);
                 self.end();
-                let token_str = self.token_kind_to_string(&token::CloseDelim(delim));
+                let token_str = self.token_kind_to_string(&token::CloseDelim(delim), None);
                 self.word(token_str);
             }
         }
@@ -884,12 +884,7 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         self.tts_to_string(&TokenStream::from_nonterminal_ast(nt))
     }
 
-    /// Print the token kind precisely, without converting `$crate` into its respective crate name.
-    fn token_kind_to_string(&self, tok: &TokenKind) -> Cow<'static, str> {
-        self.token_kind_to_string_ext(tok, None)
-    }
-
-    fn token_kind_to_string_ext(
+    fn token_kind_to_string(
         &self,
         tok: &TokenKind,
         convert_dollar_crate: Option<Span>,
@@ -959,14 +954,9 @@ pub trait PrintState<'a>: std::ops::Deref<Target = pp::Printer> + std::ops::Dere
         }
     }
 
-    /// Print the token precisely, without converting `$crate` into its respective crate name.
-    fn token_to_string(&self, token: &Token) -> Cow<'static, str> {
-        self.token_to_string_ext(token, false)
-    }
-
-    fn token_to_string_ext(&self, token: &Token, convert_dollar_crate: bool) -> Cow<'static, str> {
+    fn token_to_string(&self, token: &Token, convert_dollar_crate: bool) -> Cow<'static, str> {
         let convert_dollar_crate = convert_dollar_crate.then_some(token.span);
-        self.token_kind_to_string_ext(&token.kind, convert_dollar_crate)
+        self.token_kind_to_string(&token.kind, convert_dollar_crate)
     }
 
     fn ty_to_string(&self, ty: &ast::Ty) -> String {