[clang-tidy] Deprecate readability-deleted-default check

... For removal in next release cycle.
The clang warning that does the same thing is enabled by default and typically emits better diagnostics making this check surplus to requirements.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D97491

Author: njames93

clang-tools-extra/docs/ReleaseNotes.rst

@@ -112,6 +112,16 @@ Changes in existing checks
   function or assignment to ``nullptr``.
   Added support for pointers to ``std::unique_ptr``.
 
+Deprecated checks
+^^^^^^^^^^^^^^^^^
+
+- The :doc:`readability-deleted-default
+  <clang-tidy/checks/readability-deleted-default>` check has been deprecated.
+  
+  The clang warning `Wdefaulted-function-deleted
+  <https://clang.llvm.org/docs/DiagnosticsReference.html#wdefaulted-function-deleted>`_
+  will diagnose the same issues and is enabled by default.
+
 Improvements to include-fixer
 -----------------------------
 

clang-tools-extra/docs/clang-tidy/checks/readability-deleted-default.rst

@@ -3,20 +3,6 @@
 readability-deleted-default
 ===========================
 
-Checks that constructors and assignment operators marked as ``= default`` are
-not actually deleted by the compiler.
-
-.. code-block:: c++
-
-  class Example {
-  public:
-    // This constructor is deleted because I is missing a default value.
-    Example() = default;
-    // This is fine.
-    Example(const Example& Other) = default;
-    // This operator is deleted because I cannot be assigned (it is const).
-    Example& operator=(const Example& Other) = default;
-
-  private:
-    const int I;
-  };
+This check has been deprecated prefer to make use of the `Wdefaulted-function-deleted
+<https://clang.llvm.org/docs/DiagnosticsReference.html#wdefaulted-function-deleted>`_
+flag.