[clang-tools-extra] [clang-tidy] add modernize-use-constexpr check (PR #146553)

[via cfe-commits]

================
@@ -142,6 +142,10 @@ New checks
   Finds unscoped (non-class) ``enum`` declarations and suggests using
   ``enum class`` instead.
 
+- New :doc:`modernize-use-constexpr
+  <clang-tidy/checks/modernize/use-constexpr>` check that finds functions and
+  variables that can be declared `constexpr`.
----------------
EugeneZelenko wrote:

```suggestion
- New :doc:`modernize-use-constexpr
  <clang-tidy/checks/modernize/use-constexpr>` check.
  
   Finds functions and  variables that can be declared ``constexpr``.
```

https://github.com/llvm/llvm-project/pull/146553