Auto merge of #61541 - petrochenkov:tsp, r=oli-obk

syntax: Keep token span as a part of `Token`

In the world with proc macros and edition hygiene `Token` without a span is not self-contained.
In practice this means that tokens and spans are always stored and passed somewhere along with each other.
This PR combines them into a single struct by doing the next renaming/replacement:

- `Token` -> `TokenKind`
- `TokenAndSpan` -> `Token`
- `(Token, Span)` -> `Token`

Some later commits (https://github.com/rust-lang/rust/commit/fb6e2fe8fd6caed247857758c6c3549fe2b59527 and https://github.com/rust-lang/rust/commit/1cdee86940db892cd17239c26add5364335e895a) remove duplicate spans in `token::Ident` and `token::Lifetime`.
Those spans were supposed to be identical to token spans, but could easily go out of sync, as was noticed in https://github.com/rust-lang/rust/pull/60965#discussion_r285398523.
The `(Token, Span)` -> `Token` change is a soft pre-requisite for this de-duplication since it allows to avoid some larger churn (passing spans to most of functions classifying identifiers).

1 files changed, 6 insertions, 6 deletions

diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 57c01e9e3ef..07acfb5dc86 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -6,7 +6,7 @@ use crate::ast::{Attribute, MacDelimiter, GenericArg};
 use crate::util::parser::{self, AssocOp, Fixity};
 use crate::attr;
 use crate::source_map::{self, SourceMap, Spanned};
-use crate::parse::token::{self, BinOpToken, Nonterminal, Token};
+use crate::parse::token::{self, BinOpToken, Nonterminal, TokenKind};
 use crate::parse::lexer::comments;
 use crate::parse::{self, ParseSess};
 use crate::print::pp::{self, Breaks};
@@ -189,7 +189,7 @@ pub fn literal_to_string(lit: token::Lit) -> String {
     out
 }
 
-pub fn token_to_string(tok: &Token) -> String {
+pub fn token_to_string(tok: &TokenKind) -> String {
     match *tok {
         token::Eq                   => "=".to_string(),
         token::Lt                   => "<".to_string(),
@@ -724,10 +724,10 @@ pub trait PrintState<'a> {
     /// expression arguments as expressions). It can be done! I think.
     fn print_tt(&mut self, tt: tokenstream::TokenTree) -> io::Result<()> {
         match tt {
-            TokenTree::Token(_, ref tk) => {
-                self.writer().word(token_to_string(tk))?;
-                match *tk {
-                    parse::token::DocComment(..) => {
+            TokenTree::Token(ref token) => {
+                self.writer().word(token_to_string(&token))?;
+                match token.kind {
+                    token::DocComment(..) => {
                         self.writer().hardbreak()
                     }
                     _ => Ok(())