[turboshaft] workaround for bug in GCC 7 (again)

Bug: v8:12783
Change-Id: I2d02b4466edb1da48512b1f2d2bc14f6d5cb8dc0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3701596Reviewed-by: Andreas Haas <ahaas@chromium.org>
Auto-Submit: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81094}

src/compiler/turboshaft/graph-builder.cc

@@ -993,9 +993,9 @@ OpIndex GraphBuilder::Process(
 base::Optional<BailoutReason> BuildGraph(
     Schedule* schedule, Zone* graph_zone, Zone* phase_zone, Graph* graph,
     SourcePositionTable* source_positions) {
-  return GraphBuilder{graph_zone, phase_zone, *schedule,
-                      Assembler(graph, phase_zone), source_positions}
-      .Run();
+  GraphBuilder builder{graph_zone, phase_zone, *schedule,
+                       Assembler(graph, phase_zone), source_positions};
+  return builder.Run();
 }
 
 }  // namespace v8::internal::compiler::turboshaft