[clang] [lld] [llvm] [Clang][AArch64] Remove redundant tune args to the backend (PR #146896)

[Tomer Shafir via llvm-commits]

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@@ -163,17 +163,6 @@ getAArch64MicroArchFeaturesFromMtune(const Driver &D, StringRef Mtune,
   if (!DecodeAArch64Mcpu(D, MtuneLowerCase, Tune, Extensions))
     return false;
 
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tomershafir wrote:

ok, I planned to simplify in a followup patch, but simplified this and a bit more in a new commit

https://github.com/llvm/llvm-project/pull/146896