CI: Build for wasm32-wasi target to ensure no-multicore works

.github/workflows/ci.yml

@@ -31,6 +31,29 @@ jobs:
           command: test
           args: --verbose --release
 
+  build:
+    name: Build target ${{ matrix.target }}
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target:
+          - wasm32-wasi
+
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.51.0
+          override: true
+      - name: Add target
+        run: rustup target add ${{ matrix.target }}
+      - name: cargo fetch
+        uses: actions-rs/cargo@v1
+        with:
+          command: fetch
+      - name: Build for target
+        run: cargo build --verbose --no-default-features --target ${{ matrix.target }}
+
   bitrot:
     name: Bitrot check
     runs-on: ubuntu-latest