[clang] [clang] Enable C++17 relaxed template template argument matching by default (PR #89807)

[Vlad Serebrennikov via cfe-commits]

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@@ -0,0 +1,115 @@
+// RUN: %clang_cc1 %s -fsyntax-only -std=c++23                                     -verify=expected,new
+// RUN: %clang_cc1 %s -fsyntax-only -std=c++23 -fno-relaxed-template-template-args -verify=expected,old
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Endilll wrote:

We don't test non-conforming modes of operation in DR test suite.
This should be tested elsewhere, e.g. in SemaTemplate tests.

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