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, 2 insertions, 2 deletions

diff --git a/src/libsyntax_ext/trace_macros.rs b/src/libsyntax_ext/trace_macros.rs
index 61ef94560cc..6c74f77ff1f 100644
--- a/src/libsyntax_ext/trace_macros.rs
+++ b/src/libsyntax_ext/trace_macros.rs
@@ -17,10 +17,10 @@ pub fn expand_trace_macros(cx: &mut ExtCtxt<'_>,
     }
 
     match (tt.len(), tt.first()) {
-        (1, Some(&TokenTree::Token(_, ref tok))) if tok.is_keyword(kw::True) => {
+        (1, Some(TokenTree::Token(token))) if token.is_keyword(kw::True) => {
             cx.set_trace_macros(true);
         }
-        (1, Some(&TokenTree::Token(_, ref tok))) if tok.is_keyword(kw::False) => {
+        (1, Some(TokenTree::Token(token))) if token.is_keyword(kw::False) => {
             cx.set_trace_macros(false);
         }
         _ => cx.span_err(sp, "trace_macros! accepts only `true` or `false`"),