Return type still needs TNodification. It can be Object or Float64T.

Bug: v8:10506, v8:6949
Change-Id: I71e7ae28f3039b2e1c5c2a5c2e383c335cdec38a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2204281Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67887}