Link _output/bin/ to real binaries for this arch

This makes followup commits easier wrt finding binaries during build.

hack/lib/golang.sh

@@ -375,6 +375,8 @@ kube::golang::place_bins() {
     local platform_src="/${platform//\//_}"
     if [[ $platform == $host_platform ]]; then
       platform_src=""
+      rm -f "${THIS_PLATFORM_BIN}"
+      ln -s "${KUBE_OUTPUT_BINPATH}/${platform}" "${THIS_PLATFORM_BIN}"
     fi
 
     local full_binpath_src="${KUBE_GOPATH}/bin${platform_src}"