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

[Jessica Clarke via cfe-commits]

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@@ -0,0 +1,7 @@
+// RUN: %clang --target=riscv64 -menable-experimental-extensions -c -o /dev/null %s
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jrtc27 wrote:

Why are these clang tests? This is entirely testing llvm/ code. Never mind the weirdness of putting them in Driver/, nor the fact that they’re missing a REQUIRES: riscv-registered-target given they use the backend, they don’t belong in clang/ at all surely?

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