The icache and jump-table-assembler tests need memory that is both
writable and executable. On Mac, to do this we need to pass MAP_JIT to
mmap which is wired with the VirtualMemory::JitPermission flag.

Change-Id: If8236fa8983a4a59ef39fe777f26a02103dc6f75
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2637227Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#72217}