$ git am --3way --empty=keep --ignore-whitespace --keep-non-patch changes.patch

Applying: Remove Windows 8.1 from test queues
Using index info to reconstruct a base tree...
M	eng/pipelines/libraries/helix-queues-setup.yml
Falling back to patching base and 3-way merge...
Auto-merging eng/pipelines/libraries/helix-queues-setup.yml
CONFLICT (content): Merge conflict in eng/pipelines/libraries/helix-queues-setup.yml
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config set advice.mergeConflict false"
Patch failed at 0001 Remove Windows 8.1 from test queues
Error: The process '/usr/bin/git' failed with exit code 128