[libvpx] Copy debug symbols

[chrisaverage]

No description provided.

[NancyLi1013]

Hi @chrisaverage, thanks for your PR. I see this port failed on x64-uwp. Please refer to the following attachment to take a look.
libvpx.zip

[chrisaverage]

@NancyLi1013 Thanks for the logs. I wasn't sure what's going on.

error: failed to update mingw32 (unable to lock database)
error: failed to update mingw64 (unable to lock database)
error: failed to update msys (unable to lock database)
error: failed to synchronize all databases

It seems to error out on getting dependencies, so it has nothing to do with my change, which adds a post build install step. It also builds fine locally on my machine, so I don't think there's anything I can do on my end to fix that.

[grdowns]

Thanks for the PR, @chrisaverage! The msys problem is part of a known issue (#6688). Once the fix for it goes through in #6729 we can get meaningful results from the CI system for this PR. Thanks for your patience 😄

[grdowns]

#6729 has gone through and I've retriggered the build to test this port, which has passed. Thanks for the fix, @chrisaverage!