Merge upstream branches #35171

	# .github/workflows/example.yml

	name: Merge upstream branches
	on:
	workflow_dispatch:
	schedule:
	# actually, ~5 minutes is the highest
	# effective frequency you will get
	- cron: '0 * * * *'
	jobs:
	merge-upstream-to-all-branches:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2.4.0
	- name: Merge upstream
	run: \|
	git config --global user.name 'bot'
	git config --global user.email 'bot@noreply.com'
	for BRANCH in `git branch --list\|sed 's/\*//g'`;
	do
	git checkout $BRANCH
	git fetch --all


	git pull --unshallow # this option is very important, you would get
	# complains about unrelated histories without it.
	# (but actions/checkout@v2 can also be instructed
	# to fetch all git depth right from the start)
	git remote add upstream https://github.com/torvalds/linux
	git fetch upstream master
	git pull --rebase upstream master
	git push -f origin $BRANCH
	git remote remove upstream
	done

Provide feedback