[llvm] Update NVVM ldu/ldg intrinsics with IntrWillReturn and test for DCE (PR #98968)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,187 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt < %s -O3 -S | FileCheck %s
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arsenm wrote:

Should not use -O3 in tests, except for test/PhaseOrdering. This should be testable with a single IR pass, and then this would go in test/PassName, not test/CodeGen 

https://github.com/llvm/llvm-project/pull/98968