[clang] [clang-tools-extra] [Clang] Make the SizeType, SignedSizeType and PtrdiffType be named sugar types instead of built-in types (PR #143653)

[Matheus Izvekov via cfe-commits]

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@@ -1567,6 +1567,8 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// and bit count.
   QualType getDependentBitIntType(bool Unsigned, Expr *BitsExpr) const;
 
+  QualType getPredefinedSugarType(uint32_t KD) const;
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mizvekov wrote:

You can use enums in TypeProperties, if you simply convert between it and its underlying type when serializing.
It's also possible to add this enum type to tablegen, but this seems unnecessary, since there is a single use of it.

https://github.com/llvm/llvm-project/pull/143653