#4 palloc incorrectly allocates memory from pool children

[Nick]

pool.c is written incorrectly, when a pool is full, the
pool should
allocate another block, and not use memory from pool
children.

The pool structure should look like

struct block {
void *mem, *base;
size_t size;
struct block *next_block;
};

struct pool {
unsigned int magic;
struct block *block;

struct pool *children;

struct pool \*parent;
struct pool \*next\_sibling;

.... etc ....
};