Use the recently added -mmark-bti-property Clang flag to add
GNU_PROPERTY_AARCH64_FEATURE_1_BTI to the ELF GNU program properties.

Bug: v8:10026
Change-Id: Id35a60c9f5a8b3019313d56a142ab8f481e095a5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2543934Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Cr-Commit-Position: refs/heads/master@{#71240}