Add first pieces of support for parsing and representing 
extern "C" in C++ mode.  Patch by Mike Stump!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@45904 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/AST/DeclSerialization.cpp b/AST/DeclSerialization.cpp
index 6baa262..146ebba 100644
--- a/AST/DeclSerialization.cpp
+++ b/AST/DeclSerialization.cpp
@@ -422,3 +422,19 @@
 
   return decl;
 }
+
+//===----------------------------------------------------------------------===//
+//      LinkageSpec Serialization.
+//===----------------------------------------------------------------------===//
+
+void LinkageSpecDecl::EmitInRec(Serializer& S) const {
+  Decl::EmitInRec(S);
+  S.EmitInt(getLanguage());
+  S.EmitPtr(D);
+}
+
+void LinkageSpecDecl::ReadInRec(Deserializer& D) {
+  Decl::ReadInRec(D);
+  Language = static_cast<LanguageIDs>(D.ReadInt());
+  D.ReadPtr(this->D);
+}