Fix make.expr_closure invalid mappings

Author: A4-Tacks

crates/syntax/src/ast/syntax_factory/constructors.rs

@@ -1088,13 +1088,15 @@ impl SyntaxFactory {
         let ast = make::expr_closure(args, expr.clone()).clone_for_update();
 
         if let Some(mut mapping) = self.mappings() {
-            let mut builder = SyntaxMappingBuilder::new(ast.syntax.clone());
-            builder.map_children(
-                input,
-                ast.param_list().unwrap().params().map(|param| param.syntax().clone()),
-            );
+            let mut builder = SyntaxMappingBuilder::new(ast.syntax().clone());
             builder.map_node(expr.syntax().clone(), ast.body().unwrap().syntax().clone());
             builder.finish(&mut mapping);
+
+            let param_list = ast.param_list().unwrap();
+            let mut params_builder = SyntaxMappingBuilder::new(param_list.syntax().clone());
+            params_builder
+                .map_children(input, param_list.params().map(|param| param.syntax().clone()));
+            params_builder.finish(&mut mapping);
         }
 
         ast