[sparkplug] Flush baseline code in context serializer

JSFunctions can store a pointer to baseline code, which would trigger
that code to be serialized in the context serializer. Since we don't
support baseline code serialization, we have to flush these baseline
code pointers.

This is similar to the existing optimized code flushing.

Bug: v8:11420
Change-Id: Idabd0caea24aed484d5cf39ad0dad8c2c8180b91
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2786849Reviewed-by: Patrick Thier <pthier@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73665}

src/snapshot/context-serializer.cc

@@ -177,6 +177,9 @@ void ContextSerializer::SerializeObjectImpl(Handle<HeapObject> obj) {
     Handle<JSFunction> closure = Handle<JSFunction>::cast(obj);
     closure->ResetIfBytecodeFlushed();
     if (closure->is_compiled()) {
+      if (closure->shared().HasBaselineData()) {
+        closure->shared().flush_baseline_data();
+      }
       closure->set_code(closure->shared().GetCode(), kReleaseStore);
     }
   }