CI: Build for x86_64-unknown-linux-gnux32.

We cannot run the tests on the Ubuntu runners but we can build then.

.github/workflows/tests.yml

@@ -211,6 +211,20 @@ jobs:
       - run: cargo test --no-run --target=aarch64-apple-ios --features=std
       - run: cargo test --no-run --target=aarch64-apple-watchos-sim -Zbuild-std --features=std
 
+  build-link:
+    name: Build/Link
+    runs-on: ubuntu-22.04
+    strategy:
+      matrix:
+        target: [
+          x86_64-unknown-linux-gnux32,
+        ]
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@master
+      - name: Build Tests
+        run: cargo test --no-run --target=${{ matrix.target }} --features=std
+
   cross-link:
     name: Cross Build/Link
     runs-on: ubuntu-22.04