C++: Restore QLDoc on deprecated predicates.

Author: geoffw0

cpp/ql/src/semmle/code/cpp/commons/Printf.qll

@@ -99,10 +99,22 @@ predicate variadicFormatter(Function f, string type, int formatParamIndex, int o
   callsVariadicFormatter(f, type, formatParamIndex, outputParamIndex)
 }
 
+/**
+ * A standard function such as `vprintf` that has a format parameter
+ * and a variable argument list of type `va_arg`.
+ *
+ * DEPRECATED: Use the four argument version instead.
+ */
 deprecated predicate primitiveVariadicFormatter(TopLevelFunction f, int formatParamIndex) {
   primitiveVariadicFormatter(f, _, formatParamIndex, _)
 }
 
+/**
+ * Holds if `f` is a function such as `vprintf` that has a format parameter
+ * (at `formatParamIndex`) and a variable argument list of type `va_arg`.
+ *
+ * DEPRECATED: Use the four argument version instead.
+ */
 deprecated predicate variadicFormatter(Function f, int formatParamIndex) {
   variadicFormatter(f, _, formatParamIndex, _)
 }