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

[Yeting Kuo via cfe-commits]

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@@ -0,0 +1,7 @@
+// RUN: %clang --target=riscv64 -menable-experimental-extensions -c -o /dev/null %s
+// RUN: ! %clang --target=riscv64 -c -o /dev/null %s 2>&1 | FileCheck -check-prefixes=CHECK-ERR %s
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yetingk wrote:

Thank you. I will fix this if https://github.com/llvm/llvm-project/pull/91324 could not remove the tests.

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