Commit 3021ff4e for libheif

commit 3021ff4efd897f9d66fd6287dad33e138de27dd4
Author: Dirk Farin <dirk.farin@gmail.com>
Date:   Thu Jun 4 13:07:26 2026 +0200

    only use __visibility__ attribute with GCC/Clang compilers

diff --git a/libheif/api/libheif/heif_export.h b/libheif/api/libheif/heif_export.h
index 720a12ee..fe442f37 100644
--- a/libheif/api/libheif/heif_export.h
+++ b/libheif/api/libheif/heif_export.h
@@ -35,7 +35,8 @@
 #else
 #define LIBHEIF_API __declspec(dllimport)
 #endif
-#elif defined(HAVE_VISIBILITY) && HAVE_VISIBILITY
+#elif (defined(__GNUC__) || defined(__clang__)) && defined(HAVE_VISIBILITY) && HAVE_VISIBILITY
+// GCC-style visibility attributes.
 #ifdef LIBHEIF_EXPORTS
 #define LIBHEIF_API __attribute__((__visibility__("default")))
 #else