Also access the DescriptorArray through GetStrongValue concurrently if
the FLAG_turbo_direct_heap_access is on.

Bug: v8:7790
Change-Id: I7a36789b44e84988d498339312bf9fe92eab8e66
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2653233Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72549}