warn the unsuspecting of EVAL atrocities.

Author: adaptiveoptics

doc/Type/Cool.pod6

@@ -1257,6 +1257,10 @@ C<EVAL> is also a gateway for executing code in other languages:
 =for code :skip-test
 EVAL "use v5.20; say 'Hello from perl5!'", :lang<Perl5>;
 
+B<WARNING> There is a long-standing bug when using EVAL in long-running
+loops where memory is increasingly consumed. Consider using Callable 
+types instead of EVAL.
+
 =head2 routine EVALFILE
 
 Defined as: