mm, hugepages: add hugetlb vma mremap() test

mm, hugepages: add hugetlb vma mremap() test

[almasrymina@google.com: v8]
Link: https://lkml.kernel.org/r/20211014200542.4126947-2-almasrymina@google.com
[wanjiabing@vivo.com: remove duplicated include in hugepage-mremap]
Link: https://lkml.kernel.org/r/20211021122944.8857-1-wanjiabing@vivo.com
Link: https://lkml.kernel.org/r/20211013195825.3058275-2-almasrymina@google.com
Signed-off-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ken Chen <kenchen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill Shutemov <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>