Documentation: add an idea for an automatic refactoring

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176000 91177308-0d34-0410-b5e6-96231b3b80d8

docs/ClangTools.rst

@@ -116,4 +116,8 @@ Ideas for new Tools
 * C++ cast conversion tool.  Will convert C-style casts (``(type) value``) to
   appropriate C++ cast (``static_cast``, ``const_cast`` or
   ``reinterpret_cast``).
+* Non-member ``begin()`` and ``end()`` conversion tool.  Will convert
+  ``foo.begin()`` into ``begin(foo)`` and similarly for ``end()``, where
+  ``foo`` is a standard container.  We could also detect similar patterns for
+  arrays.