[clang] [clang][x86] Add release note entries describing recent work to making SSE intrinsics generic and usable with constexpr (PR #154737)

[Simon Pilgrim via cfe-commits]

https://github.com/RKSimon created https://github.com/llvm/llvm-project/pull/154737

I haven't created an exhaustive list of intrinsic changes, but I suppose I could if people see a strong need for it.

>From 4958154b925ad40355039c012cf2447a58f117a1 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Thu, 21 Aug 2025 12:32:55 +0100
Subject: [PATCH] [clang][x86] Add release note entries describing recent work
 to making SSE intrinsics generic and usable with constexpr

I haven't created an exhaustive list of intrinsic changes, but I suppose I could if people see a strong need for it.
---
 clang/docs/ReleaseNotes.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index fe1dd15c6f885..83e93d487a54e 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -292,6 +292,13 @@ NVPTX Support
 
 X86 Support
 ^^^^^^^^^^^
+- More SSE, AVX and AVX512 intrinsics, including initializers and general
+  arithmetic can now be used in C++ constant expressions.
+- Some SSE, AVX and AVX512 intrinsics have been converted to wrap
+  generic __builtin intrinsics.
+- NOTE: Please avoid use of the __builtin_ia32_* intrinsics - these are not 
+  guaranteed to exist in future releases, or match behaviour with previous
+  releases of clang or other compilers.
 
 Arm and AArch64 Support
 ^^^^^^^^^^^^^^^^^^^^^^^