[clang] [clang] NFC: Remove unused `FileEntry::getLastRef()` (PR #68156)

[Jan Svoboda via cfe-commits]

https://github.com/jansvoboda11 created https://github.com/llvm/llvm-project/pull/68156

The last usage of the deprecated `FileEntry::getLastRef()` was removed in #67838, let's remove it entirely.

>From 2691f3e3c5867a8102fe2b288534f6c794318d3c Mon Sep 17 00:00:00 2001
From: Jan Svoboda <jan_svoboda at apple.com>
Date: Tue, 3 Oct 2023 13:11:37 -0700
Subject: [PATCH] [clang] NFC: Remove unused `FileEntry::getLastRef()`

---
 clang/include/clang/Basic/FileEntry.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/clang/include/clang/Basic/FileEntry.h b/clang/include/clang/Basic/FileEntry.h
index c377aba2c1d2ebd..23237a9326f84b6 100644
--- a/clang/include/clang/Basic/FileEntry.h
+++ b/clang/include/clang/Basic/FileEntry.h
@@ -426,7 +426,6 @@ class FileEntry {
 public:
   ~FileEntry();
   StringRef getName() const { return LastRef->getName(); }
-  FileEntryRef getLastRef() const { return *LastRef; }
 
   StringRef tryGetRealPathName() const { return RealPathName; }
   off_t getSize() const { return Size; }