[perl #87708] use integer; $tied < $tied

[perl #87708] use integer; $tied < $tied

This is just part of #87708.

This fixes < under ‘use integer’ when the same tied scalar is used for
both operands and returns two different values. Before this commit,
get-magic would be called only once and the same value used. In 5.12.x
the operands were swapped.