Improvements to TemplateArgumentListBuilder to make it work better with parameter packs.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73272 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclTemplate.cpp b/lib/AST/DeclTemplate.cpp
index a0773f1..9526b48 100644
--- a/lib/AST/DeclTemplate.cpp
+++ b/lib/AST/DeclTemplate.cpp
@@ -247,9 +247,27 @@
     break;
   }
   
+  if (!isAddingFromParameterPack()) {
+    // Add begin and end indicies.
+    Indices.push_back(Args.size());
+    Indices.push_back(Args.size());
+  }
+
   Args.push_back(Arg);
 }
 
+void TemplateArgumentListBuilder::BeginParameterPack() {
+  assert(!isAddingFromParameterPack() && "Already adding to parameter pack!");
+  
+  Indices.push_back(Args.size());
+}
+
+void TemplateArgumentListBuilder::EndParameterPack() {
+  assert(isAddingFromParameterPack() && "Not adding to parameter pack!");
+  
+  Indices.push_back(Args.size());
+}  
+
 //===----------------------------------------------------------------------===//
 // TemplateArgumentList Implementation
 //===----------------------------------------------------------------------===//