[llvm] [AMDGPU][LTO] Introduce AMDGPUCloneModuleLDS (PR #89683)

[Anshil Gandhi via llvm-commits]

================
@@ -0,0 +1,139 @@
+//===-- AMDGPUCloneModuleLDSPass.cpp ------------------------------*- C++ -*-=//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// The purpose of this pass is to ensure that the combined module contains
----------------
gandhi56 wrote:

I updated the description, I hope the purpose is clear now.

The cloning utilities that you are using in your patch don't clone LDS globals. Instead, they are externalized in the new modules. This only results in too many unnecessary dependencies across modules which will in turn lower the target performance of parallel compilation.

https://github.com/llvm/llvm-project/pull/89683