[Github][CI] Add Windows Premerge Job for Testing #2746

	name: LLVM Premerge Checks

	permissions:
	contents: read

	on:
	pull_request:
	paths:
	- .github/workflows/premerge.yaml
	push:
	branches:
	- 'main'

	jobs:
	premerge-checks-windows:
	if: github.repository_owner == 'llvm'
	runs-on: llvm-premerge-windows-runners
	concurrency:
	group: ${{ github.workflow }}-windows-${{ github.event.pull_request.number \|\| github.sha }}
	cancel-in-progress: true
	defaults:
	run:
	shell: bash
	steps:
	- name: Checkout LLVM
	uses: actions/checkout@v4
	with:
	fetch-depth: 2
	- name: Setup ccache
	uses: hendrikmuhs/[email protected]
	with:
	variant: "sccache"
	- name: Build and Test
	continue-on-error: true
	run: \|
	modified_files=$(git diff --name-only HEAD~1...HEAD)
	modified_dirs=$(echo "$modified_files" \| cut -d'/' -f1 \| sort -u)

	echo $modified_files
	echo $modified_dirs

	. ./.ci/compute-projects.sh

	all_projects="bolt clang clang-tools-extra compiler-rt cross-project-tests flang libc libclc lld lldb llvm mlir openmp polly pstl"
	modified_projects="$(keep-modified-projects ${all_projects})"

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