initialize unclosed_delims field

Author: TaKO8Ki

compiler/rustc_parse/src/parser/path.rs

@@ -626,6 +626,7 @@ impl<'a> Parser<'a> {
             // Parse type argument.
             let is_const_fn = self.look_ahead(1, |t| t.kind == token::OpenDelim(token::Paren));
             let mut snapshot = self.clone();
+            snapshot.unclosed_delims = vec![];
             match self.parse_ty() {
                 Ok(ty) => GenericArg::Type(ty),
                 Err(err) => {