Native dependencies of ML.NET

[ericstj]

We should review and try to unify and document the native dependencies of ML.NET, in particular the VC-runtime.

Ideally we should try and build the native components in the same way that .NET Core does so that we don't impose any new requirements (eg: installing a different / specific version of the VC redist).

I checked a few DLLs using link /dump /imports and noticed a lot of instances of VCRUNTIME140 which we do not depend on for coreclr/clrcompression/clrjit/etc.

I just did this check for Windows but we should also look at a similar thing on linux.

We should also examine binary redists (like TensorFlow) so that we can understand if they are different and at least document their dependencies.

/cc @shauheen @tannergooding @danmosemsft @eerhardt

[eerhardt]

Do you know how to eliminate the import of VCRUNTIME140? I took the native build code/infrastructure from a mix of core-setup and corefx, but may have missed something in the CMake files.

[ericstj]

Here's what we do for CLRCompression. Looks like we statically link it.
https://github.com/dotnet/corefx/blob/c1788c695d4349c522fc5620eff7d3dd46a0ab5f/src/Native/Windows/CMakeLists.txt#L63-L83

Some similar options defined in CoreCLR:
https://github.com/dotnet/coreclr/blob/1938350dbf017b9de5b887e2efd8d3fd1795e3eb/configurecompiler.cmake#L530-L537

[eerhardt]

We’ve started static linking the VC Runtime in #1828. Closing.