Upgrade rust/crates/syn to 1.0.72

Test: make
Change-Id: Ie700357fdff8bb1a8c760adb67274f6b91c42eb3

1 files changed, 4 insertions, 11 deletions

diff --git a/src/generics.rs b/src/generics.rs
index de0772a7..0950c1cb 100644
--- a/src/generics.rs
+++ b/src/generics.rs
@@ -172,17 +172,10 @@ impl Generics {
 
     /// Initializes an empty `where`-clause if there is not one present already.
     pub fn make_where_clause(&mut self) -> &mut WhereClause {
-        // This is Option::get_or_insert_with in Rust 1.20.
-        if self.where_clause.is_none() {
-            self.where_clause = Some(WhereClause {
-                where_token: <Token![where]>::default(),
-                predicates: Punctuated::new(),
-            });
-        }
-        match &mut self.where_clause {
-            Some(where_clause) => where_clause,
-            None => unreachable!(),
-        }
+        self.where_clause.get_or_insert_with(|| WhereClause {
+            where_token: <Token![where]>::default(),
+            predicates: Punctuated::new(),
+        })
     }
 }