[clang] [llvm] [AArch64][RISCV] Improve the tests for --print-enabled-extensions and --print-supported-extensions (PR #97829)

[Tomas Matheson via llvm-commits]

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@@ -0,0 +1,24 @@
+// REQUIRES: aarch64-registered-target
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tmatheson-arm wrote:

I've kept them as-is so that they still correspond to the [generating script](https://gist.github.com/tmatheson-arm/333dd14cc1c95ab4ac563ed615add95d).

https://github.com/llvm/llvm-project/pull/97829