Install clang for Darwin and FreeBSD CI jobs

.gitea/workflows/build.yml

@@ -75,6 +75,7 @@ jobs:
             build-essential \
             ca-certificates \
             ccache \
+            clang \
             cmake \
             curl \
             git \
@@ -90,6 +91,12 @@ jobs:
           sudo update-alternatives --set ${{ matrix.toolchain.host }}-g++ "$(which ${{ matrix.toolchain.host }}-g++-posix)"
           sudo update-alternatives --set ${{ matrix.toolchain.host }}-gcc "$(which ${{ matrix.toolchain.host }}-gcc-posix)"
 
+      - name: Prepare FreeBSD clang aliases
+        if: ${{ matrix.toolchain.host == 'x86_64-unknown-freebsd' }}
+        run: |
+          sudo ln -sf "$(which clang)" /usr/local/bin/clang-8
+          sudo ln -sf "$(which clang++)" /usr/local/bin/clang++-8
+
       - name: Build
         run: |
           make depends target=${{ matrix.toolchain.host }} -j"$(nproc)"