macros: update syn (#5572)

tokio-macros/src/select.rs

@@ -1,7 +1,7 @@
 use proc_macro::{TokenStream, TokenTree};
 use proc_macro2::Span;
 use quote::quote;
-use syn::Ident;
+use syn::{parse::Parser, Ident};
 
 pub(crate) fn declare_output_enum(input: TokenStream) -> TokenStream {
     // passed in is: `(_ _ _)` with one `_` per branch
@@ -46,7 +46,7 @@ pub(crate) fn clean_pattern_macro(input: TokenStream) -> TokenStream {
     // If this isn't a pattern, we return the token stream as-is. The select!
     // macro is using it in a location requiring a pattern, so an error will be
     // emitted there.
-    let mut input: syn::Pat = match syn::parse(input.clone()) {
+    let mut input: syn::Pat = match syn::Pat::parse_single.parse(input.clone()) {
         Ok(it) => it,
         Err(_) => return input,
     };
@@ -58,7 +58,6 @@ pub(crate) fn clean_pattern_macro(input: TokenStream) -> TokenStream {
 // Removes any occurrences of ref or mut in the provided pattern.
 fn clean_pattern(pat: &mut syn::Pat) {
     match pat {
-        syn::Pat::Box(_box) => {}
         syn::Pat::Lit(_literal) => {}
         syn::Pat::Macro(_macro) => {}
         syn::Pat::Path(_path) => {}
@@ -94,7 +93,7 @@ fn clean_pattern(pat: &mut syn::Pat) {
             }
         }
         syn::Pat::TupleStruct(tuple) => {
-            for elem in tuple.pat.elems.iter_mut() {
+            for elem in tuple.elems.iter_mut() {
                 clean_pattern(elem);
             }
         }