[v5 14/15] mm: optimize early system hash allocations

Clients can call alloc_large_system_hash() with flag: HASH_ZERO to specify that memory that was allocated for system hash needs to be zeroed, otherwise the memory does not need to be zeroed, and client will initialize it. If memory does not need to be zero'd, call the new

[v5 14/15] mm: optimize early system hash allocations

Clients can call alloc_large_system_hash() with flag: HASH_ZERO to specify that memory that was allocated for system hash needs to be zeroed, otherwise the memory does not need to be zeroed, and client will initialize it. If memory does not need to be zero'd, call the new