breallocarray
void *breallocarray(void *, size_t, size_t);
p = breallocarray(p, 1, new_sz + 1);
mem = breallocarray(NULL, allocated, sizeof(BN_ULONG));
mem = breallocarray(mem, allocated,
stack->stack = breallocarray(stack->stack,
array->data = breallocarray(array->data, newsize, sizeof(*array->data));