[llvm] [RISCV] Add groupid/bitmask for RISC-V extension (PR #94440)

[Piyou Chen via llvm-commits]

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@@ -25,7 +25,7 @@
 class RISCVExtension<string name, int major, int minor, string desc,
                      list<SubtargetFeature> implies = [],
                      string fieldname = !subst("Feature", "Has", NAME),
-                     string value = "true">
+                     string value = "true", bits<3> groupID=0, int bitmaskShift=-1>
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BeMg wrote:

This way sound good to me. @kito-cheng Do you have other concern on it? 

https://github.com/llvm/llvm-project/pull/94440