Use mangleTemplatePrefix when we know that we're mangling a nested template name.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@82912 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index 660a36b..ab157e5 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -480,11 +480,13 @@
 void CXXNameMangler::mangleNestedName(const TemplateDecl *TD, 
                                       const TemplateArgument *TemplateArgs,
                                       unsigned NumTemplateArgs) {
+  // <nested-name> ::= N [<CV-qualifiers>] <template-prefix> <template-args> E
+
   Out << 'N';
-  manglePrefix(TD->getDeclContext());
-  mangleUnqualifiedName(TD);
   
+  mangleTemplatePrefix(TD);
   mangleTemplateArgs(TemplateArgs, NumTemplateArgs);
+  
   Out << 'E';
 }