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

[Pengcheng Wang via llvm-commits]

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@@ -52,108 +61,118 @@ class RISCVExperimentalExtension<string name, int major, int minor, string desc,
 
 def FeatureStdExtI
     : RISCVExtension<"i", 2, 1,
-                     "'I' (Base Integer Instruction Set)">;
+                     "'I' (Base Integer Instruction Set)">,
+                     RISCVExtensionBitmask<0, 0>;
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wangpc-pp wrote:

I think we should align `RISCVExtensionBitmask` with `RISCVExtension`.

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