This fixes the GN header check with Yarn. Enables further ANGLE
integration. Also fixes a number of MSVC build errors and changes
the output name of the Vulkan ICD on Windows to "vk_swiftshader"
so that it matches the .def file used in CMake.

Bug: angleproject:3876
Bug: b/140251624
Change-Id: Ie23ba965a2ee7f8b678499db22d6614f0a6666fa
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/36009Reviewed-by: Alexis Hétu <sugoi@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Jamie Madill <jmadill@chromium.org>