vma_flags_diff_pair
vma_flags_t diff = vma_flags_diff_pair(&a->flags, &b->flags);
diff = vma_flags_diff_pair(&vma->flags, &vmg->vma_flags);
vma_flags_t diff = vma_flags_diff_pair(&flags1, &flags2);
diff = vma_flags_diff_pair(&flags2, &flags1);
diff = vma_flags_diff_pair(&flags1, &flags1);
diff = vma_flags_diff_pair(&flags2, &flags2);
diff = vma_flags_diff_pair(&flags1, &flags2);
diff = vma_flags_diff_pair(&flags1, &flags2);