CI: Move non-coverage FreeBSD Cirrus CI jobs to GitHub Actions

By running them in a qemu VM on Linux runners.

.github/workflows/main.yml

@@ -115,3 +115,86 @@ jobs:
       - name: Upload coverage report
         if: matrix.coverage
         run: ci/run.sh codecov
+
+  freebsd-vm:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - job_name: FreeBSD 13.2 x64, DMD (latest)
+            freebsd_version: '13.2'
+            host_dmd: dmd
+          - job_name: FreeBSD 12.4 x64, DMD (bootstrap)
+            freebsd_version: '12.4'
+            host_dmd: dmd-2.095.0
+    name: ${{ matrix.job_name }}
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 50
+      - name: Run in qemu VM
+        uses: cross-platform-actions/action@v0.19.0
+        with:
+          operating_system: freebsd
+          version: ${{ matrix.freebsd_version }}
+          shell: bash
+          run: |
+            set -uexo pipefail
+
+            freebsd_version='${{ matrix.freebsd_version }}'
+            freebsd_major="${freebsd_version:0:2}"
+
+            export OS_NAME=freebsd
+            export MODEL=64
+            export HOST_DMD='${{ matrix.host_dmd }}'
+            export N=2
+            export FULL_BUILD=true
+            export CI_DFLAGS="-version=TARGET_FREEBSD${freebsd_major}"
+
+            #if [[ "$freebsd_major" == 12 ]]; then
+            #  sudo sed -i '' -e 's|pkg.FreeBSD.org|mirrors.xtom.com/freebsd-pkg|' /etc/pkg/FreeBSD.conf
+            #fi
+
+            bash --version
+
+            echo '::group::Install prerequisites'
+            sudo -E ci/cirrusci.sh
+            echo '::endgroup::'
+
+            echo '::group::Install host compiler'
+            ci/run.sh install_host_compiler
+            echo '::endgroup::'
+
+            echo '::group::Set up repos'
+            ln -s "$PWD" ../dmd
+
+            ref='${{ github.ref }}'
+            if [[ "$ref" =~ ^refs/pull/ ]]; then
+              REPO_BRANCH="$GITHUB_BASE_REF"
+            elif [[ "$ref" =~ ^refs/(heads|tags)/(.*)$ ]]; then
+              REPO_BRANCH="${BASH_REMATCH[2]}"
+            else
+              echo "Error: unexpected GitHub ref '$ref'" >&2
+              exit 1
+            fi
+
+            ci/run.sh setup_repos "$REPO_BRANCH"
+            echo '::endgroup::'
+
+            echo '::group::Build'
+            ci/run.sh build
+            echo '::endgroup::'
+
+            echo '::group::Test dmd'
+            ci/run.sh test_dmd
+            echo '::endgroup::'
+
+            echo '::group::Test druntime'
+            ci/run.sh test_druntime
+            echo '::endgroup::'
+
+            echo '::group::Test phobos'
+            ci/run.sh test_phobos
+            echo '::endgroup::'