[stdlib] Add codepoint slicing #23277

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	#
	# Licensed under the Apache License v2.0 with LLVM Exceptions:
	# https://llvm.org/LICENSE.txt
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	# Unless required by applicable law or agreed to in writing, software
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	name: Check PR target branch

	on:
	pull_request:
	types: [opened, edited, synchronize, reopened]

	permissions:
	contents: read
	pull-requests: read

	jobs:
	check-pr-target:
	name: Check PR target branch

	runs-on: ubuntu-latest
	timeout-minutes: 10

	defaults:
	run:
	shell: bash

	steps:
	- name: Fail if not targeting main branch
	if: ${{ github.base_ref != 'main' }}
	run: \|
	echo "PRs must be targeted to merge to the main branch!"
	echo "PR is currently targeting: \"${{ github.base_ref }}\""
	exit 1

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