Fixed a segfault on Linux kernels without CONFIG_ADVISE_SYSCALLS, e.g. Asuswrt Merlin (#564).
PartitionAlloc assumes decommitted pages are zeroed by the kernel when recommitted according to the semantics of madvise MADV_DONTNEED, but on Asuswrt Merlin its kernel does not support madvise and MADV_DONTNEED becomes a no-op, violating the assumption, then PartitionAlloc provides non-zeroed memory to calloc(), resulting in segfaults.