exercism/xperl5 — pull request #90 by kentfredric (2014-11-20 23:15:44+00:00)
Title: Force internals to compare user submitted numbers with a bignum.

Without this, users can happily simply return 2 ** 64 from 'total'
and have the test falsely "OK" it, because without bignum,

( 2 ** 64 ) == ( ( 2 ** 64 ) - 1 )

Misc styleistic changes also.