Add arm64 runner

Author: solidpixel

.github/workflows/build_test.yaml

@@ -8,6 +8,70 @@ on:
       - main
 
 jobs:
+  build-ubuntu-arm64-clang:
+    name: Ubuntu arm64 Clang
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - name: Git checkout
+        uses: actions/checkout@v4
+        with:
+          submodules: 'true'
+
+      - name: Test ImageMagick 1
+        run: |
+          convert --help
+
+      - name: Test ImageMagick
+        run: |
+          magick convert --help 2
+
+      - name: Build release
+        run: |
+          export CXX=clang++
+          mkdir build_rel
+          cd build_rel
+          cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../ -DASTCENC_ISA_NEON=ON -DASTCENC_ISA_SVE_128=ON -DASTCENC_ISA_NONE=ON -DASTCENC_PACKAGE=arm64 ..
+          make install package -j4
+
+      - name: Build debug
+        run: |
+          export CXX=clang++
+          mkdir build_dbg
+          cd build_dbg
+          cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DASTCENC_ISA_NEON=ON -DASTCENC_ISA_SVE_128=ON -DASTCENC_ISA_NONE=ON ..
+          make -j4
+
+      - name: Upload binaries
+        uses: actions/upload-artifact@v4
+        with:
+          name: astcenc-linux-arm64
+          path: |
+            build_rel/*.zip
+            build_rel/*.zip.sha256
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Get Python modules
+        run: |
+          python -m pip install --upgrade pip
+          pip install numpy Pillow
+
+      - name: Run system tests
+        run: |
+          python ./Test/astc_test_functional.py --encoder none
+          python ./Test/astc_test_functional.py --encoder neon
+          python ./Test/astc_test_functional.py --encoder sve128
+          python ./Test/astc_test_image.py --encoder none --test-set Small
+          python ./Test/astc_test_image.py --encoder neon --test-set Small
+          python ./Test/astc_test_image.py --encoder sve128 --test-set Small
+
+      - name: Run unit tests
+        run: ctest
+        working-directory: build_rel
+
   build-ubuntu-x64-clang:
     name: Ubuntu x64 Clang
     runs-on: ubuntu-22.04