[clang] [clang] CTAD: implement the missing IsDeducible constraint for alias templates (PR #89358)

[Haojian Wu via cfe-commits]

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@@ -27,7 +27,8 @@ enum TypeTrait {
   ,
 #define TYPE_TRAIT_2(Spelling, Name, Key) BTT_##Name,
 #include "clang/Basic/TokenKinds.def"
-  BTT_Last = UTT_Last // BTT_Last == last BTT_XX in the enum.
+  BTT_Last = UTT_Last
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hokein wrote:

oops, this is not intended. This was left when I reverted some changes.

https://github.com/llvm/llvm-project/pull/89358