Separate TemplateArgument instantiation logic into its own function. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73176 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index ac8997d..866f898 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -2307,6 +2307,8 @@
   TemplateName
   InstantiateTemplateName(TemplateName Name, SourceLocation Loc,
                           const TemplateArgumentList &TemplateArgs);
+  TemplateArgument Instantiate(TemplateArgument Arg,
+                               const TemplateArgumentList &TemplateArgs);
 
   void InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
                                      FunctionDecl *Function);