[clang] [X86] Add missing _mm_broadcastsi128_si256 constexpr test coverage (PR #160523)

[Simon Pilgrim via cfe-commits]

https://github.com/RKSimon created https://github.com/llvm/llvm-project/pull/160523

None

>From 0a32d46e9f5694a2aa98b04aa0820aa33e7912f9 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Wed, 24 Sep 2025 14:34:07 +0100
Subject: [PATCH] [X86] Add missing _mm_broadcastsi128_si256 constexpr test
 coverage

---
 clang/test/CodeGen/X86/avx2-builtins.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clang/test/CodeGen/X86/avx2-builtins.c b/clang/test/CodeGen/X86/avx2-builtins.c
index 20233f6106146..eff2797e87c75 100644
--- a/clang/test/CodeGen/X86/avx2-builtins.c
+++ b/clang/test/CodeGen/X86/avx2-builtins.c
@@ -263,6 +263,7 @@ __m256i test_mm_broadcastsi128_si256(__m128i a) {
   // CHECK: shufflevector <2 x i64> %{{.*}}, <2 x i64> %{{.*}}, <4 x i32> <i32 0, i32 1, i32 0, i32 1>
   return _mm_broadcastsi128_si256(a);
 }
+TEST_CONSTEXPR(match_m256i(_mm_broadcastsi128_si256(((__m128i)(__v2di){42, -99})), 42, -99, 42, -99));
 
 __m128 test_mm_broadcastss_ps(__m128 a) {
   // CHECK-LABEL: test_mm_broadcastss_ps