[Bug testsuite/80221] Contrib script to rewrite testcase from absolute to relative line numbers

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80221

--- Comment #19 from Tom de Vries <vries at gcc dot gnu.org> ---
Filed spinoff PR80552 - "Make consecutive relative line numbers more
maintainable" to capture discussion related to 'continue' line and
dg-{begin,end}-same-line-output.