add symlink for powerpc gcc and linker env

.github/workflows/ci.yml

@@ -124,12 +124,16 @@ jobs:
             target
           key: ${{ runner.os }}-powerpc64-unknown-linux-gnu-cargo-${{ hashFiles('**/Cargo.lock') }}
       - name: Install PowerPC gcc
-        run: sudo apt-get install -y gcc-powerpc64-linux-gnu
+        run: |
+          sudo apt-get install -y gcc-powerpc64-linux-gnu
+          sudo ln -s /usr/bin/powerpc64-linux-gnu-gcc-7 /usr/bin/powerpc-linux-gnu-gcc
       - name: Compile
         uses: actions-rs/cargo@v1
         with:
           command: build
           args: --release --target=powerpc64-unknown-linux-gnu
+        env: 
+          RUSTFLAGS: "-C linker=powerpc64-linux-gnu-gcc-7"
 
   publish-docker:
     name: Build and Publish Docker Image