Should you get compilation errors pointing to leveldb and atomic_pointers.h, please replace src/leveldb/port/atomic_pointer.h with this patched version from the Bitcoin source and compile again.
https://github.com/bitcoin/bitcoin/blob/master/src/leveldb/port/atomic_pointer.h
Eventually you may have to go to src/leveldb and compile manually make libmemenv.a libleveldb.a