Retain symlinks upon making universal macOS binaries

Saving symlinks is important when we build dynamic libs,
it will be needed for building QtMM + dynamic ffmpeg.

Task-number: QTBUG-120989
Pick-to: 6.6 6.5
Change-Id: I58c040a81f1fa6a3b316ace864fda0687415fd0a
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
(cherry picked from commit 231d089553)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

coin/provisioning/common/macos/makeuniversal.sh

@@ -9,11 +9,17 @@ set -e
 for dir in "$@"; do
     echo "Processing files in $dir ..."
     pushd "$dir" >/dev/null
-    find . -type f | while read -r f; do
+    find . -type f -or -type l | while read -r f; do
         dst="${f:1}"
         dstdir="$(dirname "$dst")"
         mkdir -p "$dstdir"
-        if [[ ! -f "$dst" ]]; then
+
+        if [[ -L "$f" ]]; then
+            if [[ ! -L "$dst" && ! -d "$dst" && ! -f "$dst" ]]; then
+                echo "Copying symlink $dir/$f to $dst"
+                cp -P -n "$f" "$dst"
+            fi
+        elif [[ ! -f "$dst" ]]; then
             echo "Copying $dir/$f to $dst"
             cp -c "$f" "$dst"
         elif lipo -info "$f" >/dev/null 2>&1; then