[llvm] [CodeGen][AMDGPU] TwoAddress: Only skip undef COPY at REG_SEQUENCE lowering when there is Live info or no uses for subreg (PR #175598)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,23 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -mtriple=amdgcn-amd-amdhsa -verify-machineinstrs -run-pass=twoaddressinstruction -o - %s | FileCheck %s
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arsenm wrote:

Need to test with and without live intervals? 

https://github.com/llvm/llvm-project/pull/175598