Add Fortanix to CI

.github/workflows/build.yml

@@ -36,6 +36,7 @@ jobs:
     strategy:
       matrix:
         target: [wasm32-unknown-unknown, wasm32-wasi, x86_64-unknown-redox]
+        # Clippy might not be packaged with the current nightly compiler.
         version: [stable, beta]
         include:
         - target: wasm32-unknown-unknown
@@ -44,6 +45,22 @@ jobs:
           version: 1.35.0
         - target: x86_64-unknown-redox
           version: 1.34.0
+  build-other-unstable:
+    needs: [build]
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+      with:
+        fetch-depth: 10
+    - run: rustup install nightly
+    - run: rustup default nightly
+    - run: rustup target add ${{ matrix.target }}
+    # Clippy might not be packaged with the current nightly compiler.
+    - run: cargo rustc --all-features --target ${{ matrix.target }} -- -Dwarnings
+    timeout-minutes: 5
+    strategy:
+      matrix:
+        target: [x86_64-fortanix-unknown-sgx]
   test:
     needs: [build]
     runs-on: ${{ matrix.platform }}