[Serving][Fix] Fix ABI Mismatch for FunctionTable::cache_buffers

[Ubospica]

Currently the ABI of tvm::runtime::Map will change if TVM_LOG_DEBUG is enabled or not:

// In MapNode::iterator
#if TVM_LOG_DEBUG
    uint64_t state_marker;
    ...
#else
    ...
#endif  // TVM_LOG_DEBUG

When TVM_LOG_DEBUG is inconsistent between different libraries (e.g. in TVM and in MLC-LLM), the inconsistency in ABI will lead to an invalid read/write.

This PR provides a workaround by changing the usage of tvm::runtime::Map into std::unordered_map.

Thanks to @tqchen @MasterJH5574

[MasterJH5574]

Can we revert the changes in this file? Given this test is not rather standard (like used in CI), I personally prefer a finer control of the paths in each function.

[tqchen]

Closing as it is being fixed in upstream

[Ubospica]

Plz check out apache/tvm#16728