`endian.pass.cpp` uses `std::is_enum` and friends but doesn't include `<type_traits>`. Add the missing include. Reviewed By: philnik, #libc Spies: libcxx-commits Differential Revision: https://reviews.llvm.org/D141239
`endian.pass.cpp` uses `std::is_enum` and friends but doesn't include `<type_traits>`. Add the missing include. Reviewed By: philnik, #libc Spies: libcxx-commits Differential Revision: https://reviews.llvm.org/D141239