[CI] Enable GitHub Actions in pre-commit (#4850)

Enable basic SYCL build and in-tree LIT tests on GitHub Actions in pre-commit as an experiment

Author: Alexander Batashev

.github/workflows/clang-format.yml

@@ -0,0 +1,36 @@
+name: SYCL
+
+on:
+  pull_request:
+    branches:
+    - sycl
+
+jobs:
+  lint:
+    # TODO use nightly builds of SYCL to get clang-format
+    runs-on: ubuntu-latest
+    steps:
+    - name: Get clang-format first
+      run: sudo apt-get install -yqq clang-format
+
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 2
+
+    - name: Run clang-format
+      uses: ./devops/actions/clang-format
+
+  linux_default:
+    name: Default Linux
+    # Only build and test patches, that have passed all linter checks, because
+    # the next commit is likely to be a follow-up on that job.
+    needs: lint
+    if: always() && (success() || contains(github.event.pull_request.labels.*.name, 'ignore-lint'))
+    uses: intel/llvm/.github/workflows/sycl_linux_build_and_test.yml@sycl
+    with:
+      build_runs_on: "sycl-precommit-linux"
+      build_cache_root: "/__w/"
+      build_cache_size: "8G"
+      build_artifact_suffix: "default"
+      build_cache_suffix: "default"
+

.github/workflows/sycl_precommit.yml

@@ -0,0 +1,17 @@
+name: 'clang-format'
+description: 'Run clang-format on pull request'
+runs:
+  using: "composite"
+  steps:
+  - name: Run clang-format for the patch
+    shell: bash
+    run: |
+      git diff --no-color ${GITHUB_SHA}^1 ${GITHUB_SHA} --name-only -- | grep -v "/test/" | xargs git diff -U0 --no-color ${GITHUB_SHA}^1 ${GITHUB_SHA} -- | ./clang/tools/clang-format/clang-format-diff.py -p1 -binary clang-format > ./clang-format.patch
+  # Add patch with formatting fixes to CI job artifacts
+  - uses: actions/upload-artifact@v1
+    with:
+      name: clang-format-patch
+      path: ./clang-format.patch
+  - name: Check if clang-format patch is empty
+    shell: bash
+    run: bash -c "if [ -s ./clang-format.patch ]; then cat ./clang-format.patch; exit 1; fi"