C++: Sync identical files.

cpp/ql/src/Security/CWE/CWE-020/ir/SafeExternalAPIFunction.qll

@@ -13,6 +13,7 @@ abstract class SafeExternalAPIFunction extends Function { }
 /** The default set of "safe" external APIs. */
 private class DefaultSafeExternalAPIFunction extends SafeExternalAPIFunction {
   DefaultSafeExternalAPIFunction() {
+    // implementation note: this should be based on the properties of public interfaces, rather than accessing implementation classes directly.  When we've done that, the three classes referenced here should be made fully private.
     this instanceof PureStrFunction or
     this instanceof StrLenFunction or
     this instanceof PureMemFunction