Use CAFFE2_USE_MSVC_STATIC_RUNTIME to determine when to avoid waiting for global destructors on Windows (#43532)
Summary:
We are trying to build libtorch statically (BUILD_SHARED_LIBS=OFF) then link it into a DLL. Our setup hits the infinite loop mentioned [here](https://github.com/pytorch/pytorch/blob/54c05fa34e1fbbb5096746a8ae92e27a08116de4/torch/csrc/autograd/engine.cpp#L228) because we build with `BUILD_SHARED_LIBS=OFF` but still link it all into a DLL at the end of the day.
This PR fixes the issue by changing the condition to guard on which windows runtime the build links against using the `CAFFE2_USE_MSVC_STATIC_RUNTIME` flag. `CAFFE2_USE_MSVC_STATIC_RUNTIME` defaults to ON when `BUILD_SHARED_LIBS=OFF`, so backwards compatibility is maintained.
I'm not entirely confident I understand the subtleties of the windows runtime versus linking setup, but this setup works for us and should not affect the existing builds.
Fixes https://github.com/pytorch/pytorch/issues/44470
Pull Request resolved: https://github.com/pytorch/pytorch/pull/43532
Reviewed By: mrshenli
Differential Revision: D24053767
Pulled By: albanD
fbshipit-source-id: 1127fefe5104d302a4fc083106d4e9f48e50add8
