[clang] [C23] Implement N3018: The constexpr specifier for object definitions (PR #73099)

[Mariya Podchishchaeva via cfe-commits]

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@@ -14277,6 +14325,113 @@ StmtResult Sema::ActOnCXXForRangeIdentifier(Scope *S, SourceLocation IdentLoc,
                                                       : IdentLoc);
 }
 
+static ImplicitConversionKind GetConversionKind(QualType FromType,
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Fznamznon wrote:

@AaronBallman , I think I could reuse `IsStandardConversion` to build `StandardConversionSequence` object and call it from `InitializationSequence::Perform`, so `InitializationSequence` will take care of the recursion.

https://github.com/llvm/llvm-project/pull/73099