Implement __is_empty.  Patch by Sean Hunt.

llvm-svn: 79143
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 3212923..b216ec1 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -749,6 +749,7 @@
     New->setVirtualAsWritten(true);
     Record->setAggregate(false);
     Record->setPOD(false);
+    Record->setEmpty(false);
     Record->setPolymorphic(true);
   }
   if (Tmpl->isPure()) {