Part of fix for bug 412491 (function objects cloned by XPConnect still keep hidden window alive late into shutdown). Missed this file last time. r/sr=sicking.

layout/build/nsLayoutStatics.cpp

@@ -288,6 +288,7 @@ nsLayoutStatics::Shutdown()
 
   nsAttrValue::Shutdown();
   nsContentUtils::Shutdown();
+  nsNodeInfo::ClearCache();
   nsLayoutStylesheetCache::Shutdown();
   NS_NameSpaceManagerShutdown();
   nsStyleSet::FreeGlobals();