[clang] [llvm] [RISCV] Add support of Sdext, Sdtrig extentions (PR #120936)

[Pengcheng Wang via llvm-commits]

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@@ -842,6 +842,12 @@ def HasStdExtH : Predicate<"Subtarget->hasStdExtH()">,
                  AssemblerPredicate<(all_of FeatureStdExtH),
                                     "'H' (Hypervisor)">;
 
+// Debugger extensions
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wangpc-pp wrote:

They are also `Supervisor` extensions I think since their names start with `S`.

https://github.com/llvm/llvm-project/pull/120936