[clang] [clang-tools-extra] [Clang] Unify interface for accessing template arguments as written for class/variable template specializations (PR #81642)

[Aaron Ballman via cfe-commits]

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@@ -111,6 +111,13 @@ Clang Frontend Potentially Breaking Changes
     $ clang --target=<your target triple> -print-target-triple
     <the normalized target triple>
 
+- The ``getTypeAsWritten`` member function has been removed from ``ClassTemplateSpecializationDecl`` and
+  ``VarTemplateSpecializationDecl``, and a new member function ``getTemplateArgsAsWritten`` returning a
+  ``const ASTTemplateArgumentListInfo *`` has been added to access to the explicitly written template
+  argument list of explicit specializations, partial specializations, and explicit instantiations of
+  class and variable templates. Consequently, the ``hasTypeLoc`` AST matcher will no longer match these
+  declarations and existing uses should switch to ``TemplateArgumentLoc`` matchers instead.
+
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AaronBallman wrote:

Our C++ APIs are not stable across releases, so it's very typical for folks using Clang internals to be broken between releases (this is why we strongly encourage folks to work at Tip of Tree rather than on a release-by-release basis). That's why we don't usually add release notes for internal API changes.

https://github.com/llvm/llvm-project/pull/81642