Add GitHub action for cross-platform testing

Author: karip

.github/workflows/cross-test.yml

@@ -0,0 +1,32 @@
+# Cross-platform tests for 64-bit little-endian x86_64 and 
+# 32-bit big-endian PowerPC.
+name: Cross-platform tests
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  test:
+    strategy:
+      matrix:
+        target:
+          - x86_64-unknown-linux-gnu
+          - powerpc-unknown-linux-gnu
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+      - name: Update Rust
+        run: rustup update stable
+      - name: Install cross-compilation tools
+        uses: taiki-e/[email protected]
+        with:
+          target: ${{ matrix.target }}
+      - run: ./tools/test.sh