AST: Don't treat a TemplateExpansion as a Template

Summary:
Instead of calling getAsTemplate(), call
getAsTemplateOrTemplatePattern() because it handles the
TemplateExpansion case too.

This fixes PR16997.

Reviewers: doug.gregor, rsmith

Reviewed By: rsmith

CC: cfe-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1512

llvm-svn: 189422
diff --git a/clang/test/SemaTemplate/temp_arg_template.cpp b/clang/test/SemaTemplate/temp_arg_template.cpp
index c9ce1b6..f14ff26 100644
--- a/clang/test/SemaTemplate/temp_arg_template.cpp
+++ b/clang/test/SemaTemplate/temp_arg_template.cpp
@@ -60,3 +60,14 @@
 struct unbox_args {
   typedef typename Primitive::template call<F> x;
 };
+
+template <template <typename> class... Templates>
+struct template_tuple {};
+template <typename T>
+struct identity {};
+template <template <typename> class... Templates>
+template_tuple<Templates...> f7() {}
+
+void foo() {
+  f7<identity>();
+}