ci: add arm64x build workflow

.github/workflows/build-arm64x.yml

@@ -0,0 +1,21 @@
+name: build (arm64x)
+
+on: [push]
+
+jobs:
+  build-arm64x:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Pull AMD64 image
+      run: |
+        docker pull gemesa/arm64x:latest
+        
+    - name: Run AMD64 container
+      run: |
+        docker run \
+          --rm \
+          -v "${{ github.workspace }}":/workspace \
+          gemesa/arm64x:latest \
+          make arm64x

Dockerfilex

@@ -0,0 +1,10 @@
+FROM fedora:latest
+
+RUN dnf upgrade --refresh -y
+RUN dnf install make -y
+RUN dnf install llvm -y
+RUN dnf install gcc-aarch64-linux-gnu -y
+RUN dnf install binutils-aarch64-linux-gnu -y
+RUN dnf install sysroot-aarch64-fc41-glibc -y
+
+WORKDIR /workspace