Avoid warnings.

llvm-svn: 72976
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index 11b9275..a534164 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -240,6 +240,7 @@
 //===----------------------------------------------------------------------===//
 void TemplateArgumentListBuilder::push_back(const TemplateArgument& Arg) {
   switch (Arg.getKind()) {
+  default: break;
   case TemplateArgument::Type:
     assert(Arg.getAsType()->isCanonical() && "Type must be canonical!");
     break;