C++: Add change note

Author: Robert Marsh

change-notes/1.23/analysis-cpp.md

@@ -35,3 +35,5 @@ The following changes in version 1.23 affect C/C++ analysis in all applications.
 * There is now a `DataFlow::localExprFlow` predicate and a
   `TaintTracking::localExprTaint` predicate to make it easy to use the most
   common case of local data flow and taint: from one `Expr` to another.
+* The predicates `Declaration.hasStdName()` and `Declaration.hasGlobalOrStdName`
+  have been added, simplifying handling of C++ standard library functions.