When testing with the Fall Creators Update SDK and clang-cl I hit the following error:

FAILED: obj/media/midi/midi/midi_manager_winrt.obj
../../third_party/llvm-build/Release+Asserts/bin/clang-cl.exe /nologo /showIncludes  @obj/media/midi/midi/midi_manager_winrt.obj.rsp /c ../../media/midi/midi_manager_winrt.cc /Foobj/media/midi/midi/midi_manager_winrt.obj /Fd"obj/media/midi/midi_cc.pdb"
In file included from ../../media/midi/midi_manager_winrt.cc:19:
c:\src\chromium3\src\third_party\depot_tools\win_toolchain\vs_files\264b4f41744f2e87ca68693d939ee19e681c4fc3\win_sdk\bin\..\..\win_sdk\include\10.0.16299.0\winrt\wrl/event.h(316,65):  error: missing 'typename' prior to dependent type name 'DelegateHelper::Interface'
    return DelegateHelper::Traits::Callback<TDelegateInterface, DelegateHelper::Interface>(Details::Forward<TLambda>(callback));
                                                                ^~~~~~~~~~~~~~~~~~~~~~~~~
../../media/midi/midi_manager_winrt.cc(648,14):  note: in instantiation of function template specialization 'Microsoft::WRL::Callback<ABI::Windows::Foundation::ITypedEventHandler<ABI::Windows::Devices::Midi::MidiInPort *, ABI::Windows::Devices::Midi::MidiMessageReceivedEventArgs *>, (lambda at ../../media/midi/midi_manager_winrt.cc:650:13)>' requested here
        WRL::Callback<
             ^
In file included from ../../media/midi/midi_manager_winrt.cc:19:
c:\src\chromium3\src\third_party\depot_tools\win_toolchain\vs_files\264b4f41744f2e87ca68693d939ee19e681c4fc3\win_sdk\bin\..\..\win_sdk\include\10.0.16299.0\winrt\wrl/event.h(316,65):  error: missing 'typename' prior to dependent type name 'DelegateHelper::Interface'
    return DelegateHelper::Traits::Callback<TDelegateInterface, DelegateHelper::Interface>(Details::Forward<TLambda>(callback));
                                                                ^~~~~~~~~~~~~~~~~~~~~~~~~
../../media/midi/midi_manager_winrt.cc(469,14):  note: in instantiation of function template specialization 'Microsoft::WRL::Callback<ABI::Windows::Foundation::IAsyncOperationCompletedHandler<ABI::Windows::Devices::Midi::MidiInPort *>, (lambda at ../../media/midi/midi_manager_winrt.cc:470:13)>' requested here
        WRL::Callback<IAsyncOperationCompletedHandler<RuntimeType*>>(
             ^
...

The code in question in wrl\event.h is here:

// Construct a COM/WinRT delegate (an object with an Invoke() method) from a lambda.
// Check the return from this function for null to detect out of memory (E_OUTOFMEMORY) failure case.
template<typename TDelegateInterface, typename TLambda>
ComPtr<typename Details::DelegateArgTraitsHelper<TDelegateInterface>::Interface> Callback(TLambda&& callback) throw()
{
    using DelegateHelper = Details::DelegateArgTraitsHelper<TDelegateInterface>;
    return DelegateHelper::Traits::Callback<TDelegateInterface, DelegateHelper::Interface>(Details::Forward<TLambda>(callback));
}

I have confirmed that adding 'typename' where request resolves the error and allows this file to compile. I filed a VS/SDK bug here:

https://developercommunity.visualstudio.com/content/problem/141824/missing-typename-error-when-compiling-fall-creator.html