Drop the ASTContext.h include from DeclFriend.h and DeclTemplate.h.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159723 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/DeclFriend.cpp b/lib/AST/DeclFriend.cpp
index 6e3bd8d..553d170 100644
--- a/lib/AST/DeclFriend.cpp
+++ b/lib/AST/DeclFriend.cpp
@@ -12,12 +12,18 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclFriend.h"
 #include "clang/AST/DeclTemplate.h"
 using namespace clang;
 
 void FriendDecl::anchor() { }
 
+FriendDecl *FriendDecl::getNextFriendSlowCase() {
+  return cast_or_null<FriendDecl>(
+                           NextFriend.get(getASTContext().getExternalSource()));
+}
+
 FriendDecl *FriendDecl::Create(ASTContext &C, DeclContext *DC,
                                SourceLocation L,
                                FriendUnion Friend,