opt does not load poolalloc

Hi,

I compiled the poolalloc from SVN head.

opt complains about missing symbol PoolAlloc::ID when I try to load
libpoolalloc.so. Defining PoolAlloc::ID is not enough, since it is
reused in PoolAllocPassAllPools.

The append patch fixes the problem for me.

Kind regards,
            Martin

Index: include/poolalloc/PoolAllocate.h