DefineClass uses the ClassBoilerplate to directly construct the
property descriptor array or dictionary for defining the class
constructor and prototype, skipping use of the LookupIterator and the
encapsulated protector update logic. This patch adds manual calls
to UpdateProtector(), which is in particular relevant for the
isConcatSpreadable protector.

Bug: v8:9837
Change-Id: I7b9d8105d41f5f0f826ca2ce35d6bf3d1aeee6e7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1863644
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64368}