[clang] [clang] deprecate frelaxed-template-template-args, make it on by default (PR #89807)

[Matheus Izvekov via cfe-commits]

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@@ -1133,8 +1133,8 @@ <h2 id="cxx17">C++17 implementation status</h2>
     <!-- Issaquah 2016 papers -->
     <tr>
       <td>Matching template template parameters to compatible arguments</td>
-      <td><a href="https://wg21.link/p0522r0">P0522R0</a></td>
-      <td class="partial" align="center">Partial <a href="#p0522">(10)</a></td>
+      <td><a href="https://wg21.link/p0522r0">P0522R0</a> (<a href="#dr">DR</a>)</td>
+      <td class="full" align="center">Clang 4 <a href="#p0522">(10)</a></td>
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mizvekov wrote:

This entry was one of the review requests from @zygoloid in the original phab PR: https://reviews.llvm.org/D109496?id=384873#3031693

I think saying we implemented in Clang 4 is more accurate, we even explain in the note that it was behind a switch. But still users have known about it and have been using it for a long time.

https://github.com/llvm/llvm-project/pull/89807