This warning seems to be emitted since we build with `-shared` for PIE
by default through our `default-buildmode-pie.patch`. Building with
shared linkage requires depending on CGO. The patch, however, doesn't
force a dependency on CGO. As with android we need to force external
linkage in order to always depend on CGO thereby resolving this warning.
I am unsure whether this is really the best way to fix the problem since
I don't know enough about the internals of the go compiler. However, I
am under the impression that the person who originally committed the
patch isn't familiar with the compiler internals either. Thus it's
probably ok to push this as is.
