[clang] [Clang] Add __builtin_get_counted_by builtin (PR #102549)

[Bill Wendling via cfe-commits]

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@@ -4774,3 +4774,9 @@ def ArithmeticFence : LangBuiltin<"ALL_LANGUAGES"> {
   let Attributes = [CustomTypeChecking, Constexpr];
   let Prototype = "void(...)";
 }
+
+def GetCountedBy : Builtin {
+  let Spellings = ["__builtin_get_counted_by"];
+  let Attributes = [NoThrow];
+  let Prototype = "size_t*(void*)";
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bwendling wrote:

Oooo! I was looking for something like `CustomTypeChecking`. I'll check into it.

https://github.com/llvm/llvm-project/pull/102549