Back out bad piece of r80272. Will look at fixing this a different way.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@80273 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaDecl.cpp

@@ -4311,10 +4311,7 @@ CreateNewDecl:
   New->setLexicalDeclContext(CurContext);
 
   // Set the access specifier.
-  // FIXME: This used to be skipped for friend tag decls, but it led to an
-  // assertion in Decl::CheckAccessDeclContext(); once various issues with
-  // friend class decls are sorted out, this should be revisited.
-  if (!Invalid)
+  if (!Invalid && TUK != TUK_Friend)
     SetMemberAccessSpecifier(New, PrevDecl, AS);
 
   if (TUK == TUK_Definition)

test/SemaTemplate/instantiate-friend-class.cpp

@@ -1,4 +1,6 @@
 // RUN: clang-cc -fsyntax-only -verify %s
+// XFAIL
+// PR4794
 
 template <class T> class X
 {