Core: use ngx_palloc_small() to allocate ngx_pool_large_t.
Core: use ngx_palloc_small() to allocate ngx_pool_large_t.

This structure cannot be allocated as a large block anyway, otherwise that will
result in infinite recursion, since each large allocation requires to allocate
another ngx_pool_large_t.

The room for the structure is guaranteed by the NGX_MIN_POOL_SIZE constant.

firebase/nginx,firebase/nginx,firebase/nginx,firebase/nginx