Using vars pragma is discouraged and has been superseded by 'our' declarations
available in Perl v5.6.0 or later.
This commit is about replacing the usage of 'vars' pragma
by 'our' in 'ext' directory.
Switch from two-argument form. Filehandle cloning is still done with the two
argument form for backward compatibility.
Committer: Get all porting tests to pass. Increment some $VERSIONs.
Run: ./perl -Ilib regen/mk_invlists.pl; ./perl -Ilib regen/regcharclass.pl
For: RT #130122