CI: Add extra Phobos tests (publictests and betterc make targets)

ci/run.sh

@@ -135,6 +135,21 @@ test_druntime() {
 # build and run Phobos unit tests
 test_phobos() {
     make -j$N -C ../phobos MODEL=$MODEL unittest
+
+    if [[ "$OS_NAME" == "windows" ]]; then
+        echo "FIXME: Skipping publictests on Windows (test failures)"
+    elif [[ "${DMD:-dmd}" =~ "gdmd" ]]; then
+        echo "Skipping publictests with GDC host compiler (no installed dub)"
+    else
+        source ~/dlang/*/activate # activate host compiler - need dub
+
+        make -j$N -C ../phobos MODEL=$MODEL publictests
+        make -j$N -C ../phobos MODEL=$MODEL publictests NO_BOUNDSCHECKS=1
+
+        make -j$N -C ../phobos MODEL=$MODEL betterc
+
+        deactivate # deactivate host compiler
+    fi
 }
 
 # test dub package