[llvm] [analyzer] Add missing include <unordered_map> to llvm/lib/Support/Z3Solver.cpp (PR #106410)

[via llvm-commits]

llvmbot wrote:

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Failed to cherry-pick: 63c3de4

https://github.com/llvm/llvm-project/actions/runs/10613204816

Please manually backport the fix and push it to your github fork.  Once this is done, please create a [pull request](https://github.com/llvm/llvm-project/compare)

https://github.com/llvm/llvm-project/pull/106410