add gc scan tests #2

	name: gcscan

	on:
	schedule:
	- cron: '0 0 * * *'
	push:
	branches:
	- master

	jobs:
	gcscan:
	runs-on: ubuntu-latest
	steps:
	- name: Install packages
	run: sudo apt update -y && sudo apt-get install -y csvkit datamash
	- uses: actions/setup-go@v4
	with:
	go-version: '1.22'
	check-latest: true
	- uses: actions/checkout@v4
	- name: go mod tidy
	run: \|
	mkdir bench
	cd bench
	awk '{if($0 ~ "// gcscan.go"){a=1;b=1};if($0 ~ "```" && b=1){b=0};if (a&&b) {print}}' ../README.md > gcscan.go
	go mod init bench
	go mod tidy
	go mod edit -replace github.com/phuslu/lru=../
	cat go.mod
	- name: GC Tests
	working-directory: ./bench
	run: \|
	echo -e 'GCScan\tCacheSize\tScanTime' > memusage.txt
	for name in nottl phuslu lxzan ristretto freelru ecache otter theine cloudflare ccache hashicorp; do
	for cachesize in 100000 200000 400000 1000000 2000000 4000000; do
	env GODEBUG=gctrace=1 go run gcscan.go $name $cachesize \| tee gcscan-$name-$cachesize.txt
	echo -e "$name\t$cachesize\t$(tail -20 gcscan.txt \| awk -F+ '{a+=$2}END{print int(a/20)}') ms" \| tee -a gcscan.txt
	done
	done
	cat gcscan.txt
	- name: GC Results
	working-directory: ./bench
	run: \|
	cat gcscan.txt \| datamash --header-in crosstab 1,2 unique 3 \| tee >(head -1) \| tail -n +2 \| sort -k12 -n \| datamash transpose \| tee >(head -1) \| tail -n +2 \| sort -n \| datamash transpose \| csvlook

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