[Runtime] Export GraphRuntime in tvm_runtime.dll

[soiferj]

Currently, the GraphRuntime class is unusable in C++ from Windows. This change exposes the class.

@jmorrill would you be able to take a look?

[jmorrill]

@soiferj This is where it gets a little embarrassing for me. I've never been able to get a good link to tvm_runtime.dll, even using tvm_runtime_pack.cc without some other changes...So like killing a a fly with a rocket launcher, I work off this CMake change:

https://github.com/jmorrill/tvm/blob/cc0b1e750512b690bbecc9e98a30f7a9945843b1/CMakeLists.txt#L282 aka "export everything"

I can try again to get this tvm_runtime_pack.cc method to give me a link and then see if your fix solves it :).

[jmorrill]

@soiferj Thank you. This fixes my need to have set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON) and can re-enable INTERPROCEDURAL_OPTIMIZATION on it.

tvm_runtime.dll links fine on VS2019!

[soiferj]

Awesome! Thanks @jmorrill. Would you mind approving the PR if it looks good? :)

[jmorrill]

I don't think I'm authoritative on approving PRs (or if i know how to do it).

Works on my machine.

Thanks!