Method get_chunk_end

src/core/test/mem_alloc.cpp:83–93

    size_t nr_free() const { return m_nr_free; }

    void* get_chunk_end(void* addr) {
        MGB_LOCK_GUARD(m_mtx);
        auto iter = m_addr2size.upper_bound(addr);
        mgb_assert(
                iter != m_addr2size.begin() &&
                (iter == m_addr2size.end() || iter->first > addr));
        --iter;
        void* end = (char*)iter->first + iter->second;
        mgb_assert(iter->first <= addr && end > addr);
        return end;
    }
};

class AllocChecker {