Implement support for null non-type template arguments for non-type
template parameters of pointer, pointer-to-member, or nullptr_t
type in C++11. Fixes PR9700 / <rdar://problem/11193097>.

llvm-svn: 154219
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 621658c..3879907 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -325,6 +325,8 @@
     return IsSameValue(*Arg1.getAsIntegral(), *Arg2.getAsIntegral());
       
   case TemplateArgument::Declaration:
+    if (!Arg1.getAsDecl() || !Arg2.getAsDecl())
+      return !Arg1.getAsDecl() && !Arg2.getAsDecl();
     return Context.IsStructurallyEquivalent(Arg1.getAsDecl(), Arg2.getAsDecl());
       
   case TemplateArgument::Template: