[llvm] Export `LLVM_VERSION_MAJOR` CMake variable to `PARENT_SCOPE` (PR #83346)

[Benoit Jacob via llvm-commits]

https://github.com/bjacob updated https://github.com/llvm/llvm-project/pull/83346

>From 502e3deaeeae2b7c00c6187f7e31f6c59a4c016e Mon Sep 17 00:00:00 2001
From: Benoit Jacob <jacob.benoit.1 at gmail.com>
Date: Wed, 28 Feb 2024 17:00:28 -0500
Subject: [PATCH] llvm-version-major

---
 llvm/CMakeLists.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/llvm/CMakeLists.txt b/llvm/CMakeLists.txt
index 651f17879fad24..111c8cfa15d828 100644
--- a/llvm/CMakeLists.txt
+++ b/llvm/CMakeLists.txt
@@ -28,6 +28,8 @@ if(NOT DEFINED LLVM_VERSION_SUFFIX)
   set(LLVM_VERSION_SUFFIX git)
 endif()
 
+set_directory_properties(PROPERTIES LLVM_VERSION_MAJOR "${LLVM_VERSION_MAJOR}")
+
 if (NOT PACKAGE_VERSION)
   set(PACKAGE_VERSION
     "${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}${LLVM_VERSION_SUFFIX}")