[clang] [Clang] Clarify diagnostic notes for implicitly generated deduction guides (PR #96084)

[Younan Zhang via cfe-commits]

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@@ -108,8 +108,11 @@ struct Foo {
   Foo(T const (&)[N]);
 };
 
+// FIXME: Prefer non-canonical template arguments in the deduction guide?
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zyn0217 wrote:

Good to know that, remove the FIXME now.

https://github.com/llvm/llvm-project/pull/96084