[PATCH] D55777: [libcxx] Portability fix: add missing includes and static_casts.

[Andrey Maksimov via Phabricator]

amakc11 added a comment.

I don't use clang. The log of running tests including `poisoned_hash_helper.hpp` is attached.
F7718494: poisoned_helper_tests.log <https://reviews.llvm.org/F7718494>


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  https://reviews.llvm.org/D55777/new/

https://reviews.llvm.org/D55777