Fix issue parsing filenames with space

Author: ianayl

devops/actions/run-tests/benchmark/action.yml

@@ -233,6 +233,7 @@ runs:
 
       cd "./llvm-ci-perf-results"
       git add .
+      IFS="$(printf '\n')"
       for diff in $(git diff HEAD --name-only); do
         mkdir -p "../cached_changes/$(dirname $diff)"
         cp "$diff" "../cached_changes/$diff"