[clang] [clang] Implement `__is_pointer_interconvertible_base_of()` (PR #88473)

[via cfe-commits]

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@@ -19710,6 +19710,27 @@ bool Sema::IsLayoutCompatible(QualType T1, QualType T2) const {
   return isLayoutCompatible(getASTContext(), T1, T2);
 }
 
+//===-------------- Pointer interconvertibility ----------------------------//
+
+bool Sema::IsPointerInterconvertibleBaseOf(const TypeSourceInfo *Base,
+                                           const TypeSourceInfo *Derived) {
+  QualType BaseT = Base->getType().getCanonicalType().getUnqualifiedType();
+  QualType DerivedT =
+      Derived->getType().getCanonicalType().getUnqualifiedType();
----------------
Sirraide wrote:

Wouldn’t just `getCanonicalTypeUnqualified()` do the same thing as `getCanonicalType().getUnqualifiedType()`—or is there a difference between the two that I’m not aware of?

https://github.com/llvm/llvm-project/pull/88473