Upload build-log.txt if it exists.

hack/jenkins/upload-to-gcs.sh

@@ -111,6 +111,10 @@ function upload_artifacts_and_build_result() {
       gsutil -m -q -o "GSUtil:use_magicfile=True" cp -a "${gcs_acl}" -r -c \
         -z log,txt,xml "${artifacts_path}" "${gcs_build_path}/artifacts" || continue
     fi
+    if [[ -e "${WORKSPACE}/build-log.txt" ]]; then
+      echo "Uploading build log"
+      gsutil -q cp -Z -a "${gcs_acl}" "${WORKSPACE}/build-log.txt" "${gcs_build_path}"
+    fi
     # Mark this build as the latest completed.
     echo "Marking build ${BUILD_NUMBER} as the latest completed build"
     echo "${BUILD_NUMBER}" | \