This code consumes more and more memory:

$ perl -e 'while (1) { eval qq{my $x : shared}; }'

perl-5.16 (F≥18) is affected.

Fixes by upstream commit:

commit 9fa29fa7929b4167c5491b792c5cc7e4365a2839
Author: Father Chrysostomos <sprout>
Date:   Wed Sep 19 21:53:51 2012 -0700

    [perl #114764] Stop my vars with attrs from leaking
    
    S_apply_attrs was creating a SV containing a stash name, that was
    later to be put in a const op, which would take care of freeing it.
    But it didn’t free it for a my variable, because the branch where that
    const op was created didn’t apply.  So move the creation of that SV
    inside the branch that uses it, otherwise it leaks.  This leak was the
    result of commit 95f0a2f1ffc6.