Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Z/src/ngltools/ngltools_export.h

@@ -0,0 +1,19 @@
+
+
+#pragma once
+
+#ifndef NGLTOOLS_EXPORT
+# ifdef BUILD_STATIC_LIBRARIES
+#  define NGLTOOLS_EXPORT
+# else
+#  ifdef WIN32
+#   ifdef MAKE_NGLTOOLS_LIB
+#    define NGLTOOLS_EXPORT __declspec(dllexport)
+#   else
+#    define NGLTOOLS_EXPORT __declspec(dllimport)
+#   endif
+#  else
+#   define NGLTOOLS_EXPORT  __attribute__((visibility("default")))
+#  endif
+# endif
+#endif