Bug 1550628 - Correctly handle OOM. r=iain

Differential Revision: https://phabricator.services.mozilla.com/D30597

--HG--
extra : moz-landing-system : lando

js/src/frontend/Parser.cpp

@@ -7433,7 +7433,7 @@ GeneralParser<ParseHandler, Unit>::fieldInitializerOpt(
   }
 
   ListNodeType statementList = handler_.newStatementList(wholeInitializerPos);
-  if (!argsbody) {
+  if (!statementList) {
     return null();
   }
   handler_.addStatementToList(statementList, exprStatement);