Add CI workflow for unittest on linux-aarch64 with atomic library fix

Author: chizkiyahu

.github/workflows/pull.yml

@@ -34,7 +34,42 @@ jobs:
 
         # Run tests
         pytest
- 
+
+  unittest-linux-aarch64:
+    name: unittest-linux-aarch64
+    uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
+    strategy:
+      fail-fast: false
+    with:
+      runner: linux.arm64.2xlarge
+      submodules: 'true'
+      ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
+      timeout: 90
+      script: |
+        set -ex
+        
+        # On some Linux aarch64 systems, the "atomic" library is not found during linking.
+        # To work around this, replace "atomic" with the literal ${ATOMIC_LIB} so the
+        # build system uses the full path to the atomic library.
+        file="third-party/sentencepiece/src/CMakeLists.txt"
+        sed 's/list(APPEND SPM_LIBS "atomic")/list(APPEND SPM_LIBS ${ATOMIC_LIB})/' \
+          "$file" > "${file}.tmp" && mv "${file}.tmp" "$file"
+      
+        grep -n 'list(APPEND SPM_LIBS ${ATOMIC_LIB})' "$file" && \
+          echo "the file $file has been modified for atomic to use full path"
+
+        
+        cmake -DCMAKE_BUILD_TYPE=Debug test -Bbuild/test
+        cmake --build build/test -j9 --config Debug
+        pushd build/test && ctest && popd
+
+        # Install tokenizers
+        pip install . -v
+        pip install pytest blobfile transformers>=4.53.1
+
+        # Run tests
+        pytest
+
   unittest-windows:
     uses: pytorch/test-infra/.github/workflows/windows_job.yml@main
     with: