Log Message:
Update to 0.26
--------------
0.26  Tue 28 Apr 2015 12:31:17 BST
    - There is a new experimental option in bleadperl under which one ought not \ 
to use
      the op_sibling field directly. Quoting from perlguts.pod:

        Starting in version 5.21.2, perls built with the experimental
        define C<-DPERL_OP_PARENT> add an extra boolean flag for each op,
        C<op_moresib>.  When not set, this indicates that this is the last \ 
op in an
        C<OpSIBLING> chain. This frees up the C<op_sibling> field on \ 
the last
        sibling to point back to the parent op. Under this build, that field is
        also renamed C<op_sibparent> to reflect its joint role. The macro
        C<OpSIBLING(o)> wraps this special behaviour, and always returns \ 
NULL on
        the last sibling.  With this build the C<op_parent(o)> function can be
        used to find the parent of any op. Thus for forward compatibility, you
        should always use the C<OpSIBLING(o)> macro rather than accessing
        C<op_sibling> directly.

      Thanks to Reini Urban for the patch.