test_utils: Test whether mmap PROT_WRITE fails
Writing is what our guard is supposed to prevent, let's try to mmap it for writing. It seems FreeBSD still allows PROT_READ for sealed-for-writing mmaps.
Writing is what our guard is supposed to prevent, let's try to mmap it for writing. It seems FreeBSD still allows PROT_READ for sealed-for-writing mmaps.