Add lld installation and test steps for Linux (#3213)

Author: haricot

.github/workflows/rust-ci.yml

@@ -42,7 +42,17 @@ jobs:
         if: runner.os == 'macOS'
         run: rm -f .cargo/config.toml
       - uses: dtolnay/rust-toolchain@stable
-      - run: cargo test --workspace
+      - name: Install lld (Linux only)
+        if: runner.os == 'Linux'
+        run: sudo apt-get update && sudo apt-get install -y lld
+      - name: Run tests (with lld on Linux)
+        if: runner.os == 'Linux'
+        env:
+          RUSTFLAGS: "-Clinker-features=-lld"
+        run: cargo test --workspace
+      - name: Run tests (Windows & macOS)
+        if: runner.os != 'Linux'
+        run: cargo test --workspace
 
   fmt:
     name: Rustfmt