and avoid runtime calls for struct allocation. We can load the
map from the instance and do the allocation in a CSA builtin.

Bug: v8:7748
Change-Id: I76dfcb6c28800d69046b3d7381d3b8ba774fbf09
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2169099
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67617}