[llvm] AMDGPU/NewPM Port GCNDPPCombine to NPM (PR #105816)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,55 @@
+//=======- GCNDPPCombine.h - optimization for DPP instructions ---==========//
+//
+// 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 pass combines V_MOV_B32_dpp instruction with its VALU uses as a DPP src0
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arsenm wrote:

These comments are more useful in the implementation file 

https://github.com/llvm/llvm-project/pull/105816