libdl/rtl-obj.c: synchronize cache after code relocation.

Memory content changes caused by relocation has to be
propagated to memory/cache level which is used/snooped
during instruction cache fill.

Closes #2438

cpukit/libdl/rtl-rap.c

@@ -970,6 +970,8 @@ rtems_rtl_rap_file_load (rtems_rtl_obj_t* obj, int fd)
   if (!rtems_rtl_rap_relocate (&rap, obj))
     return false;
 
+  rtems_rtl_obj_synchronize_cache (obj);
+
   return true;
 }