Refactoring for immutable nodes

Src/AST/Myc.Ast.JSON.pas

@@ -739,11 +739,7 @@ begin
     for i := 0 to fieldsArray.Count - 1 do
     begin
         fieldObj := fieldsArray.Items[i] as TJSONObject;
-        fields[i] :=
-            TRecordFieldLiteral.Create(
-                TKeywordNode.Create(TKeywordRegistry.Intern(fieldObj.GetValue<string>('Name'))),
-                JsonToNode(fieldObj.GetValue('Value'))
-            );
+        fields[i] := TRecordFieldLiteral.Create(TAst.Keyword(fieldObj.GetValue<string>('Name')), JsonToNode(fieldObj.GetValue('Value')));
     end;
     Result := TAst.RecordLiteral(fields);
 end;