Implement malloc_domainset_aligned(9).
Tested by: pho
(cherry picked from commit 3b15beb30b3b4ba17bae3d1d43c8c04ff862bb57)
(cherry picked from commit 0781c79d4872a84a8ebeee3b5eb5520a682b8e7b)
(cherry picked from commit 1ac7c34486ab9177c2472278739568d4607e1acc)