Conversion from '__int64' to 'long', possible loss of data

llvm-project\libcxx\test\std\time\time.hms\time.hms.members\seconds.pass.cpp(38): note: see reference to function template instantiation 'long check_seconds<std::chrono::seconds>(Duration)' being compiled
        with
        [
            Duration=std::chrono::seconds
        ]
llvm-project\libcxx\test\std\time\time.hms\time.hms.members\seconds.pass.cpp(31): warning C4244: 'return': conversion from '_Rep' to 'long', possible loss of data
        with
        [
            _Rep=__int64
        ]

Reviewed By: #libc, Mordante

Differential Revision: https://reviews.llvm.org/D129928