[llvm] [Github][CI] Add Windows Premerge Job for Testing (PR #122661)

[Aiden Grossman via llvm-commits]

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@@ -70,3 +70,65 @@ jobs:
           export CXX=/opt/llvm/bin/clang++
 
           ./.ci/monolithic-linux.sh "$(echo ${linux_projects} | tr ' ' ';')" "$(echo ${linux_check_targets})" "$(echo ${linux_runtimes} | tr ' ' ';')" "$(echo ${linux_runtime_check_targets})"
+
+  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 at v4
+        with:
+          fetch-depth: 2
+      - name: Setup ccache
+        uses: hendrikmuhs/ccache-action at v1.2.14
+        with:
+          variant: "sccache"
+          max-size: "2000M"
+      - name: Compute Projects
+        id: vars
+        run: |
+          modified_files=$(git diff --name-only HEAD~1...HEAD)
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boomanaiden154 wrote:

Yes. We get a merge commit at the top of the branch that we checkout that we diff rather than all the individual commits.

https://github.com/llvm/llvm-project/pull/122661