[clang] [clang-tools-extra] [clang-tidy] Add new check: `readability-redundant-typename` (PR #161574)

[Victor Chernyakin via cfe-commits]

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@@ -208,6 +208,13 @@ New checks
 
   Detect redundant parentheses.
 
+- New :doc:`readability-redundant-typename
+  <clang-tidy/checks/readability/redundant-typename>` check.
+
+  Finds redundant uses of the ``typename`` keyword. Can be used
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localspook wrote:

An alias is something I hadn't considered. It's an interesting idea. Looking at the [existing aliases](https://clang.llvm.org/extra/clang-tidy/checks/list.html#check-aliases), it looks like almost all of them are from a specific style guide module (like `hicpp` or `llvm`) to one of the "widely-applicable" modules (like `modernize` or `performance`). This would be the first case where one check is in two widely-applicable modules, and I don't think it needs *that* much visibility.

https://github.com/llvm/llvm-project/pull/161574