[llvm] [X86] Use GFNI for LZCNT vXi8 ops (PR #141888)

[Simon Pilgrim via llvm-commits]

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@@ -0,0 +1,16 @@
+; RUN: llc -mtriple=x86_64 -mattr=+gfni,+ssse3 < %s | FileCheck %s
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RKSimon wrote:

theres no need for this new test file - the existing test coverage in gfni-lzcnt.ll should be enough

https://github.com/llvm/llvm-project/pull/141888