Add CI run for bindings generation (though we'll allow it to fail)

Author: TheBlueMatt

.github/workflows/build.yml

@@ -94,3 +94,23 @@ jobs:
         run: cd fuzz && cargo test --verbose --color always
       - name: Run fuzzers
         run: cd fuzz && ./ci-fuzz.sh
+
+  check_bindings:
+    runs-on: ubuntu-latest
+    env:
+      TOOLCHAIN: stable
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v2
+      - name: Install Rust ${{ env.TOOLCHAIN }} toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ env.TOOLCHAIN }}
+          override: true
+          profile: minimal
+      - name: Install cbindgen
+        run: cargo install --force cbindgen
+      - name: Rebuild bindings, and check the sample app builds + links
+        run: ./genbindings.sh
+      - name: Check that the latest bindings are in git
+        run: [ "$(git diff)" != "" ] && exit 1