add dedicated RecordUpdate tag to parse ast

compiler/parse/src/ast.rs

@@ -98,6 +98,12 @@ pub enum Expr<'a> {
         final_comments: &'a [CommentOrNewline<'a>],
     },
 
+    RecordUpdate {
+        update: &'a Loc<Expr<'a>>,
+        fields: &'a [Loc<AssignedField<'a, Expr<'a>>>],
+        final_comments: &'a [CommentOrNewline<'a>],
+    },
+
     Record {
         update: Option<&'a Loc<Expr<'a>>>,
         fields: &'a [Loc<AssignedField<'a, Expr<'a>>>],

compiler/parse/src/expr.rs

@@ -1393,6 +1393,7 @@ fn expr_to_pattern_help<'a>(arena: &'a Bump, expr: &Expr<'a>) -> Result<Pattern<
         | Expr::Record {
             update: Some(_), ..
         }
+        | Expr::RecordUpdate { .. }
         | Expr::UnaryOp(_, _) => Err(()),
 
         Expr::Str(string) => Ok(Pattern::StrLiteral(string.clone())),