Connect my checkstyle9.pl script to a action.

Sponsored by:		Netflix

.github/workflows/cross-bootstrap-tools.yml

@@ -2,7 +2,7 @@ name: Cross-build Kernel
 
 on:
   push:
-    branches: [ main, 'stable/13' ]
+    branches: [ main, 'stable/13', 'stable/14' ]
   pull_request:
     branches: [ main ]
 

.github/workflows/style.yml

@@ -0,0 +1,37 @@
+name: Style Checker
+
+on:
+  push:
+    branches: [ main, 'stable/13', 'stable/14' ]
+  pull_request: # maybe pull_request_target
+    branches: [ main ]
+#    types: [ opened, reopened, edited ]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Style Checker
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 100
+          ref: ${{ github.event.pull_request.head.sha }}
+      - name: Sanity
+        run: |
+	  git log --oneline -100
+	  ls .git/refs/heads
+      - name: Dump GitHub context
+        env:
+          GITHUB_CONTEXT: ${{ toJson(github) }}
+        run: echo "$GITHUB_CONTEXT"
+      - name: Install packages
+        run: |
+          sudo apt-get update --quiet || true
+          sudo apt-get -yq --no-install-suggests --no-install-recommends install perl
+      - name: Run checker
+        run: |
+          tools/build/checkstyle9.pl ${{ github.event.pull_request.base.sha }}..${{ github.event.pull_request.head.sha }}