[turboshaft] workaround for bug in GCC 7

It seems that GCC 7 doesn't support constructor calls with curly braces
inside of expressions.

Bug: v8:12827
Change-Id: I7b8ff792de1f67a45af6e2e2d82808f57d23b66c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3606230
Auto-Submit: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Nico Hartmann <nicohartmann@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80170}

src/compiler/turboshaft/recreate-schedule.cc

@@ -900,7 +900,8 @@ Node* ScheduleBuilder::ProcessOperation(const SwitchOp& op) {
 RecreateScheduleResult RecreateSchedule(const Graph& graph,
                                         CallDescriptor* call_descriptor,
                                         Zone* graph_zone, Zone* phase_zone) {
-  return ScheduleBuilder{graph, call_descriptor, graph_zone, phase_zone}.Run();
+  ScheduleBuilder builder{graph, call_descriptor, graph_zone, phase_zone};
+  return builder.Run();
 }
 
 }  // namespace v8::internal::compiler::turboshaft