Revert of [serializer/debugger] hide scripts in the snapshot from the...

Revert of [serializer/debugger] hide scripts in the snapshot from the debugger. (patchset #5 id:80001 of https://codereview.chromium.org/2826073004/ )

Reason for revert:
failure in the custom snapshot build: http://builders/V8%20Linux64%20-%20custom%20snapshot%20-%20debug/builds/14178

Original issue's description:
> [serializer/debugger] hide scripts in the snapshot from the debugger.
>
> R=jgruber@chromium.org
> BUG=v8:6274
>
> Review-Url: https://codereview.chromium.org/2826073004
> Cr-Commit-Position: refs/heads/master@{#44745}
> Committed: https://chromium.googlesource.com/v8/v8/+/215e668256a205aba7bacf2da8b68ddfc573d3dd

TBR=jgruber@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:6274

Review-Url: https://codereview.chromium.org/2831893002
Cr-Commit-Position: refs/heads/master@{#44747}

src/debug/debug.cc

@@ -2059,13 +2059,13 @@ void Debug::OnAsyncTaskEvent(debug::PromiseDebugActionType type, int id,
 }
 
 void Debug::ProcessCompileEvent(v8::DebugEvent event, Handle<Script> script) {
-  if (!script->IsUserJavaScript() && script->type() != i::Script::TYPE_WASM) {
-    return;
-  }
   // Attach the correct debug id to the script. The debug id is used by the
   // inspector to filter scripts by native context.
   script->set_context_data(isolate_->native_context()->debug_context_id());
   if (ignore_events()) return;
+  if (!script->IsUserJavaScript() && script->type() != i::Script::TYPE_WASM) {
+    return;
+  }
   if (!debug_delegate_) return;
   SuppressDebug while_processing(this);
   DebugScope debug_scope(this);

src/snapshot/startup-serializer.cc

@@ -73,10 +73,6 @@ void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
     Address original_address = Foreign::cast(info->getter())->foreign_address();
     Foreign::cast(info->js_getter())->set_foreign_address(original_address);
     accessor_infos_.Add(info);
-  } else if (obj->IsScript() && Script::cast(obj)->IsUserJavaScript()) {
-    // Reset type for user scripts embedded in the start-up snapshot to hide
-    // them from the debugger.
-    Script::cast(obj)->set_type(Script::TYPE_EXTENSION);
   }
 
   // Object has not yet been serialized.  Serialize it here.

test/cctest/test-serialize.cc

@@ -638,11 +638,6 @@ TEST(CustomSnapshotDataBlob1) {
         CompileRun("f()")->Int32Value(isolate1->GetCurrentContext());
     CHECK_EQ(42, result.FromJust());
     CHECK(CompileRun("this.g")->IsUndefined());
-    v8::Local<v8::Value> f = CompileRun("f");
-    i::Handle<i::JSFunction> function =
-        i::Handle<i::JSFunction>::cast(v8::Utils::OpenHandle(*f));
-    // Being part of the snapshot hides a script from the debugger.
-    CHECK(!function->shared()->IsSubjectToDebugging());
   }
   isolate1->Dispose();
 }