[clang] [Clang] Fix a use-after-move issue in SubsumptionChecker (PR #164781)

[Younan Zhang via cfe-commits]

https://github.com/zyn0217 created https://github.com/llvm/llvm-project/pull/164781

Spotted by Shafik in https://github.com/llvm/llvm-project/pull/161671#discussion_r2453641287

>From ccb96a36e12f263ce3142ca9bdd1c5ea201e683e Mon Sep 17 00:00:00 2001
From: Younan Zhang <zyn7109 at gmail.com>
Date: Thu, 23 Oct 2025 17:13:37 +0800
Subject: [PATCH] [Clang] Fix a use-after-move issue in SubsumptionChecker

Spotted by Shafik
---
 clang/lib/Sema/SemaConcept.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
index f77fca2a69e00..70149464b3a99 100644
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -2669,8 +2669,9 @@ FormulaType SubsumptionChecker::Normalize(const NormalizedConstraint &NC) {
     });
 
     if (Compound.getCompoundKind() == FormulaType::Kind) {
+      unsigned SizeLeft = Left.size();
       Res = std::move(Left);
-      Res.reserve(Left.size() + Right.size());
+      Res.reserve(SizeLeft + Right.size());
       std::for_each(std::make_move_iterator(Right.begin()),
                     std::make_move_iterator(Right.end()), Add);
       return Res;