Log Message:
p5-PPIx-Regexp: update to 0.056.

0.056		2018-03-07	T. R. Wyant
    Support removal of unescaped literal left curlys after left parens,
    which was deprecated in 5.27.8. No actual change in output yet,
    since deprecation is not tracked, but the perl_version_removed()
    logic is there.

    Add next_element() and kin. These are analogous to next_sibling()
    and kin, but will cross over from content proper into structure
    (beginning and end delimiters, etc) and vice versa.

    Correct requirements_for_perl() for impossible regular expression.
    It now returns '! $]' when the components of the regexp are valid, but
    none are valid under any specific version of Perl. It used to think all
    Perls were OK when this happened.

    Add the alpha_assertions introduced in 5.27.9.

    Handle 5.27.9's change from +script_run to *script_run, and support
    *sr as a synonym.