[turbofan] Remove redundant call to SerializePrototype.

The maps in question are already processed in
NativeContextData::Serialize.

R=jarin@chromium.org

Bug: v8:7790
Change-Id: Ifbbff64e10458605b09c74fe09e574b2f2659839
Reviewed-on: https://chromium-review.googlesource.com/c/1317809
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57247}

src/compiler/js-call-reducer.cc

@@ -463,7 +463,6 @@ Reduction JSCallReducer::ReduceFunctionPrototypeBind(Node* node) {
   MapRef map = is_constructor
                    ? native_context().bound_function_with_constructor_map()
                    : native_context().bound_function_without_constructor_map();
-  map.SerializePrototype();
   if (!map.prototype().equals(prototype)) return NoChange();
 
   // Make sure we can rely on the {receiver_maps}.