[clang] [RISCV] Make RequiredExtensions for intrinsics scalable to more than 32 extensions. NFC (PR #132895)

[Craig Topper via cfe-commits]

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@@ -519,6 +517,9 @@ struct RVVIntrinsicRecord {
   // e.g. vadd
   const char *OverloadedName;
 
+  // Required target features for this intrinsic.
+  uint32_t RequiredExtensions[(RVV_REQ_NUM + 31) / 32];
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topperc wrote:

FeatureBits is very large and will waste a lot of space.

We also don't have access to the RISCV feature enum if RISCV isn't passed to cmake's LLVM_TARGETS_TO_BUILD.

https://github.com/llvm/llvm-project/pull/132895