[clang] Revert "[Clang] Remove unneeded template keyword" (PR #71478)

[Shafik Yaghmour via cfe-commits]

https://github.com/shafik created https://github.com/llvm/llvm-project/pull/71478

Reverts llvm/llvm-project#71435

This is failing on some build bots e.g.: https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/62315/consoleFull#-3939952849ba4694-19c4-4d7e-bec5-911270d8a58c

>From 61934f800bb6d1a987e214bd7424f4dc1c58d4c3 Mon Sep 17 00:00:00 2001
From: Shafik Yaghmour <shafik.yaghmour at intel.com>
Date: Mon, 6 Nov 2023 18:22:07 -0800
Subject: [PATCH] Revert "[Clang] Remove unneeded template keyword (#71435)"

This reverts commit 9c346780dc1deed1c5362fcfca874e281c53e6e0.
---
 clang/include/clang/AST/Redeclarable.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/clang/include/clang/AST/Redeclarable.h b/clang/include/clang/AST/Redeclarable.h
index be022bf5322ad61..091bb886f2d4962 100644
--- a/clang/include/clang/AST/Redeclarable.h
+++ b/clang/include/clang/AST/Redeclarable.h
@@ -114,7 +114,9 @@ class Redeclarable {
 
     bool isFirst() const {
       return Link.is<KnownLatest>() ||
-             Link.get<NotKnownLatest>().is<UninitializedLatest>();
+             // FIXME: 'template' is required on the next line due to an
+             // apparent clang bug.
+             Link.get<NotKnownLatest>().template is<UninitializedLatest>();
     }
 
     decl_type *getPrevious(const decl_type *D) const {