[llvm] [TableGen] Print a warning when a Processor contains duplicate Features / TuneFeatures (PR #137864)

[Rahul Joshi via llvm-commits]

================
@@ -357,8 +367,10 @@ unsigned SubtargetEmitter::cpuKeyValues(raw_ostream &OS,
   for (const Record *Processor : ProcessorList) {
     StringRef Name = Processor->getValueAsString("Name");
     ConstRecVec FeatureList = Processor->getValueAsListOfDefs("Features");
+    checkDuplicateCPUFeatures(Name, "Features", FeatureList);
----------------
jurahul wrote:

Can the same feature appear in both Features and TuneFeatures? If not, should we check that as well?

https://github.com/llvm/llvm-project/pull/137864