lib/zstd.h
  - disable visibility modifications ZSTDLIB_VISIBILITY + ZSTDLIB_VISIBILITY
lib/common/zstd_errrors.h
  - disable visibility modifications ZSTDERRORLIB_VISIBILITY + ZSTDERRORLIB_API
CMakeModules/AddZstdCompilationFlags.cmake
  - add EnableCompilerFlag("-fvisibility=hidden" true true)
  - add EnableCompilerFlag("-fPIC" true true)