p4raw-id: //depot/perl@5234
for representing Unicode strings, and for comparing version "numbers"
using the string comparison operators, C<cmp>, C<gt>, C<lt> etc.
--If there are more than two dots in the literal, the leading C<v> may be
++If there are two or more dots in the literal, the leading C<v> may be
omitted.
Such literals are accepted by both C<require> and C<use> for doing a version