ci: add i386 unit test run

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

.github/workflows/test.yml

@@ -35,7 +35,7 @@ jobs:
         # criu repo
         sudo add-apt-repository -y ppa:criu/ppa
         # apt-add-repository runs apt update so we don't have to
-        sudo apt -q install libseccomp-dev criu skopeo
+        sudo apt -q install libseccomp-dev criu skopeo gcc-multilib
 
     - name: install go ${{ matrix.go-version }}
       uses: actions/setup-go@v2
@@ -69,6 +69,13 @@ jobs:
       if: matrix.rootless != 'rootless'
       run: sudo -E PATH="$PATH" -- make localunittest
 
+    # We need to continue support for 32-bit ARM.
+    # However, we do not have 32-bit ARM CI, so we use i386 for testing 32bit stuff.
+    # We are not interested in providing official support for i386.
+    - name: unit test (i386)
+      if: matrix.rootless != 'rootless'
+      run: sudo -E PATH="$PATH" -- make GOARCH=386 localunittest
+
     - name: add rootless user
       if: matrix.rootless == 'rootless'
       run: |