[turbolizer] Print schedule for stub code

We lost the print functionality for stub schedules somewhere on the
way. This re-adds the appropriate call to TraceSchedule to get it
going again.

Bug: v8:7327
Change-Id: I245823b440542708410d2253f9f4e78b2e22f3c9
Reviewed-on: https://chromium-review.googlesource.com/1047270Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53038}

src/compiler/pipeline.cc

@@ -1996,6 +1996,8 @@ Handle<Code> Pipeline::GenerateCodeForCodeStub(
     pipeline.Run<PrintGraphPhase>("Machine");
   }
 
+  TraceSchedule(data.info(), data.isolate(), data.schedule());
+
   pipeline.Run<VerifyGraphPhase>(false, true);
   return pipeline.GenerateCode(call_descriptor);
 }