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, 3 insertions, 3 deletions

diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs
index b5be45547cf..c78215b77a9 100644
--- a/src/libsyntax_ext/format.rs
+++ b/src/libsyntax_ext/format.rs
@@ -149,16 +149,16 @@ fn parse_args<'a>(
         } // accept trailing commas
         if named || (p.token.is_ident() && p.look_ahead(1, |t| *t == token::Eq)) {
             named = true;
-            let ident = if let token::Ident(i, _) = p.token {
+            let name = if let token::Ident(name, _) = p.token.kind {
                 p.bump();
-                i
+                name
             } else {
                 return Err(ecx.struct_span_err(
                     p.span,
                     "expected ident, positional arguments cannot follow named arguments",
                 ));
             };
-            let name: &str = &ident.as_str();
+            let name: &str = &name.as_str();
 
             p.expect(&token::Eq)?;
             let e = p.parse_expr()?;