[llvm] [AMDGPU] Add mark last scratch load pass (PR #75512)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,140 @@
+//===-- AMDGPUMarkLastScratchLoad.cpp -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Mark scratch load/spill instructions which are guaranteed to be the last time
+// this scratch slot is used so it can be evicted from caches.
+//
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arsenm wrote:

Maybe add a TODO to handle general, non-spill, stack access?

https://github.com/llvm/llvm-project/pull/75512