[clang] [clang][Sema] Move computing enum width and type to a separate function (PR #120965)

[Ilia Kuklin via cfe-commits]

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@@ -20008,6 +20008,87 @@ bool Sema::IsValueInFlagEnum(const EnumDecl *ED, const llvm::APInt &Val,
   return !(FlagMask & Val) || (AllowMask && !(FlagMask & ~Val));
 }
 
+bool Sema::ComputeBestEnumProperties(ASTContext &Context, EnumDecl *Enum,
+                                     bool is_cpp, bool isPacked,
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kuilpd wrote:

Maybe better to put this function into `EnumDecl` itself? It has `ASTContext` within it filled on both Sema and LLDB side, and then `EnumDecl`  can fill it's own `BestType` and `BestPromotionType` fields using this function. 

https://github.com/llvm/llvm-project/pull/120965