[clang] [NFC] use `StringSet::insert(iter, iter)` instead for loop to insert (PR #69851)

[Congcong Cai via cfe-commits]

https://github.com/HerrCai0907 created https://github.com/llvm/llvm-project/pull/69851

None

>From 37f6822035845f120d2fb995a607561621c3892e Mon Sep 17 00:00:00 2001
From: Congcong Cai <congcongcai0907 at 163.com>
Date: Sun, 22 Oct 2023 00:27:04 +0800
Subject: [PATCH] [NFC] use `StringSet::insert(iter, iter)` instead for loop to
 insert elements

---
 clang/lib/ARCMigrate/ObjCMT.cpp | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/clang/lib/ARCMigrate/ObjCMT.cpp b/clang/lib/ARCMigrate/ObjCMT.cpp
index 8458a72d6a2482b..4fa4ab8d42b7d3e 100644
--- a/clang/lib/ARCMigrate/ObjCMT.cpp
+++ b/clang/lib/ARCMigrate/ObjCMT.cpp
@@ -123,9 +123,7 @@ class ObjCMigrateASTConsumer : public ASTConsumer {
         NSIntegerTypedefed(nullptr), NSUIntegerTypedefed(nullptr),
         Remapper(remapper), FileMgr(fileMgr), PPRec(PPRec), PP(PP),
         IsOutputFile(isOutputFile), FoundationIncluded(false) {
-    // FIXME: StringSet should have insert(iter, iter) to use here.
-    for (const std::string &Val : AllowList)
-      AllowListFilenames.insert(Val);
+    AllowListFilenames.insert(AllowList.begin(), AllowList.end());
   }
 
 protected: