cmake: robustly locate RTI libraries via recursive search under RTI_DIR

cmake/FindRTI.cmake

@@ -149,6 +149,16 @@ SET(_RTI_LIBS nddscore nddsc nddscpp2 rtiroutingservice)
 SET(_libs "")
 SET(_lib_vars "")
 
+# Try recursive search for RTI libraries under RTI_DIR to handle vendor arch subdirs (e.g. x64Linux4gcc8.5.0)
+foreach(_lib IN LISTS _RTI_LIBS)
+  file(GLOB_RECURSE _found_libs "${RTI_DIR}/lib/**/lib${_lib}.*")
+  list(LENGTH _found_libs _found_count)
+  if(_found_count GREATER 0)
+    list(GET _found_libs 0 _first)
+    set("RTI_${_lib}_LIBRARY" "${_first}" CACHE STRING "RTI library ${_lib}" FORCE)
+  endif()
+endforeach()
+
 FOREACH(_lib ${_RTI_LIBS})
   SET(_libname "RTI_${_lib}_LIBRARY")
   IF (NOT ${_libname})