[llvm] [VFABI] Create FunctionType for vector functions (PR #75058)

[Paul Walker via llvm-commits]

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@@ -1477,6 +1480,37 @@ void VFABI::getVectorVariantNames(
   }
 }
 
+std::optional<FunctionType *>
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paulwalker-arm wrote:

Can this just be `FunctionType *`? We don't need to distinguish between `std::nullopt` and `nullptr` so I don't think the optional provides any value.

https://github.com/llvm/llvm-project/pull/75058