Summary:
When built as a static library on Win32, `zstd` has an output name like `zstd_static.lib` and `zstd_staticd.lib`:
https://github.com/facebook/zstd/blob/69baaee3e42f90dedea2c946bc19bfeac4e782ee/build/cmake/lib/CMakeLists.txt#L140
So `FindZstd.cmake` should also take this into consideration.
Pull Request resolved: https://github.com/facebook/folly/pull/1120

Reviewed By: yfeldblum

Differential Revision: D15149814

Pulled By: Orvid

fbshipit-source-id: 298809a524468ab5aa68e58f5fef0cbb0f366051