[clang] [llvm] [RISCV] Teach .option arch to support experimental extensions. (PR #89727)

[Yeting Kuo via llvm-commits]

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@@ -169,6 +169,9 @@ void riscv::getRISCVTargetFeatures(const Driver &D, const llvm::Triple &Triple,
     Features.push_back("-relax");
   }
 
+  if (!Args.hasArg(options::OPT_menable_experimental_extensions))
+    Features.push_back("+no-experimental-ext");
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yetingk wrote:

Fixed. Only use +experimental feature.

https://github.com/llvm/llvm-project/pull/89727