Avoid freeing the allocated monitors on shutdown, it seems to cause c…

…rashes

when running with SGEN, since SGEN writes to those arrays in:

==29095==    at 0x6844E5: add_or_remove_disappearing_link (sgen-gc.c:4143)
==29095==    by 0x6845F8: mono_gc_register_disappearing_link (sgen-gc.c:4167)
==29095==    by 0x67DE35: clear_domain_process_object (sgen-gc.c:1384)
==29095==    by 0x67DEA3: clear_domain_process_major_object_callback (sgen-gc.c:1400)
==29095==    by 0x6DE2DC: major_iterate_objects (sgen-marksweep.c:692)
==29095==    by 0x67E00B: mono_gc_clear_domain (sgen-gc.c:1459)

mono/metadata/monitor.c

@@ -129,10 +129,12 @@ mono_monitor_cleanup (void)
 
 	/*DeleteCriticalSection (&monitor_mutex);*/
 
+	/* FIXME: This seems to cause crashes with SGEN
 	for (marray = monitor_allocated; marray; marray = next) {
 		next = marray->next;
 		g_free (marray);
 	}
+	*/
 }
 
 /*