Checking both gnu and llvm binutils on CI.

.github/workflows/compilability_check.yml

@@ -6,6 +6,7 @@ jobs:
     strategy:
       matrix:
         abi: [ "armeabi-v7a", "arm64-v8a", "x86", "x86_64" ]
+        binutils: [ "gnu", "llvm" ]
       fail-fast: false
     steps:
       - uses: actions/checkout@v2
@@ -18,4 +19,4 @@ jobs:
       - name: Executing the script
         run: |
           export ANDROID_SDK_HOME=$ANDROID_HOME
-          ./ffmpeg-android-maker.sh -all-free -all-gpl -android=18 -abis=${{ matrix.abi }}
+          ./ffmpeg-android-maker.sh -all-free -all-gpl -android=21 -abis=${{ matrix.abi }} -binutils=${{ matrix.binutils }}