Support TemplateTemplateParmDecl for PCH.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@107884 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHWriterDecl.cpp b/lib/Frontend/PCHWriterDecl.cpp
index 7c672bd..81cb792 100644
--- a/lib/Frontend/PCHWriterDecl.cpp
+++ b/lib/Frontend/PCHWriterDecl.cpp
@@ -963,7 +963,14 @@
 }
 
 void PCHDeclWriter::VisitTemplateTemplateParmDecl(TemplateTemplateParmDecl *D) {
-  assert(false && "cannot write TemplateTemplateParmDecl");
+  VisitTemplateDecl(D);
+  // TemplateParmPosition.
+  Record.push_back(D->getDepth());
+  Record.push_back(D->getPosition());
+  // Rest of TemplateTemplateParmDecl.
+  Writer.AddTemplateArgumentLoc(D->getDefaultArgument(), Record);
+  Record.push_back(D->defaultArgumentWasInherited());
+  Code = pch::DECL_TEMPLATE_TEMPLATE_PARM;
 }
 
 void PCHDeclWriter::VisitStaticAssertDecl(StaticAssertDecl *D) {