<chrono>: Windows x64 ABI: bad performance with wrapped data like chrono::seconds

I observed that if I return for example a std::chrono::seconds object from a not inlined method / function my code becomes 5 times slower compared to direct usage of long long (x64 compilation on Windows).

The reason for this is the Windows x64 ABI. See:
https://docs.microsoft.com/en-us/cpp/build/x64-calling-convention?view=vs-2019

According to this spec each value (which has a base class or custom constructor) is returned via stack and not via using a register. I would really like to use these wrapped data structures and others. But I can't accept such a big performance hit.

Is there any way to explicitly tell the compiler to return such simple values via register (exactly like the underlying data)?

To reproduce the issue I show you some simple code:

__declspec(noinline)
std::chrono::seconds Foo() {
    return std::chrono::seconds{ 42 };
}

__declspec(noinline)
long long Foo2() {
    return 42;
}

int main()
{
    auto f = Foo();
    auto f2 = Foo2();
    std::cout << "Hello World!\n" << *reinterpret_cast<long long*>(&f) << f2;
}

The code results in the following assembly:

Foo:

00007FF737C31000  mov         qword ptr [rcx],2Ah  
00007FF737C31007  mov         rax,rcx

Instead of Foo2:

00007FF737C31010  mov         eax,2Ah

For my project I use only a single compiler and don't care ABI compatibility across compilers.

vNext note: Resolving this issue will require breaking binary compatibility. We won't be able to accept pull requests for this issue until the vNext branch is available. See #169 for more information.

Read the Windows x64 calling-convention specification and the reproduction in the issue first, then review #169 for the vNext constraint. A complete resolution would require an agreed STL or ABI change and a way to validate the generated assembly; no repository file or test is identified.