[clang] [clang-tools-extra] [Clang] Add __type_list_dedup builtin to deduplicate types in template arguments (PR #106730)

[Richard Smith via cfe-commits]

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@@ -309,7 +309,10 @@ enum BuiltinTemplateKind : int {
   BTK__make_integer_seq,
 
   /// This names the __type_pack_element BuiltinTemplateDecl.
-  BTK__type_pack_element
+  BTK__type_pack_element,
+
+  /// This names the __type_list_dedup BuiltinTemplateDecl.
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zygoloid wrote:

This name seems inconsistent with the previous builtin: using the `__type_pack` prefix for both would be more uniform.

https://github.com/llvm/llvm-project/pull/106730