The frame pointer did not point to the previous frame pointer, which
made the stack non-iterable with SafeStackFrameIterator.

This can cause pointer authentication failures when CFI is enabled,
as we expect the value stored above the previous frame pointer to
be a return address.

Bug: v8:10026
Change-Id: Ia55181038b1b277d0a6df519f1e7f61859847b1a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2614429Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Cr-Commit-Position: refs/heads/master@{#72036}