[compiler-rt] [X86] Support -march=pantherlake, clearwaterforest (PR #69277)

[Phoebe Wang via llvm-commits]

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@@ -1249,6 +1249,18 @@ def ProcessorFeatures {
   list<SubtargetFeature> ARLSFeatures =
     !listconcat(SRFFeatures, ARLSAdditionalFeatures);
 
+  // Pantherlake
+  list<SubtargetFeature> PTLAdditionalFeatures = [FeaturePREFETCHI];
+  list<SubtargetFeature> PTLFeatures =
+    !listconcat(ARLSFeatures, PTLAdditionalFeatures);
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phoebewang wrote:

EAS doesn't say `Panther Lake` has these `ARLSAdditionalFeatures`

https://github.com/llvm/llvm-project/pull/69277