[llvm] [ADT] Replace Min with variadic std::min (PR #157390)

[Kazu Hirata via llvm-commits]

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@@ -226,19 +227,13 @@ struct PointerSumTypeHelper : MemberTs... {
   };
 
   // Next we need to compute the number of bits available for the discriminant
-  // by taking the min of the bits available for each member. Much of this
-  // would be amazingly easier with good constexpr support.
-  template <uintptr_t V, uintptr_t... Vs>
-  struct Min : std::integral_constant<
-                   uintptr_t, (V < Min<Vs...>::value ? V : Min<Vs...>::value)> {
-  };
-  template <uintptr_t V>
-  struct Min<V> : std::integral_constant<uintptr_t, V> {};
-  enum { NumTagBits = Min<MemberTs::TraitsT::NumLowBitsAvailable...>::value };
+  // by taking the min of the bits available for each member.
+  static constexpr int NumTagBits =
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kazutakahirata wrote:

@kuhar I think `int` is slightly better because `NumLowBitsAvailable` is declared pretty consistently as `int` across the codebase.

https://github.com/llvm/llvm-project/pull/157390