Return MaybeHandle from NewConsString.

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index 5fce1dd94a677df4ade93876e6ac78496c08d1c1..d0e01fc371521e28b744cae920a07387912aa3f0 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -2974,9 +2974,11 @@ Statement* Parser::ParseForStatement(ZoneStringList* labels, bool* ok) {
         // TODO(keuchel): Move the temporary variable to the block scope, after
         // implementing stack allocated block scoped variables.
         Factory* heap_factory = isolate()->factory();
-        Handle<String> tempstr =
-            heap_factory->NewConsString(heap_factory->dot_for_string(), name);
-        RETURN_IF_EMPTY_HANDLE_VALUE(isolate(), tempstr, 0);
+        Handle<String> tempstr;
+        ASSIGN_RETURN_ON_EXCEPTION_VALUE(
+            isolate(), tempstr,
+            heap_factory->NewConsString(heap_factory->dot_for_string(), name),
+            0);
         Handle<String> tempname = heap_factory->InternalizeString(tempstr);
         Variable* temp = scope_->DeclarationScope()->NewTemporary(tempname);
         VariableProxy* temp_proxy = factory()->NewVariableProxy(temp);