turns out we cant maike a jump trie that starts with a NOTHING regop

turns out we cant maike a jump trie that starts with a NOTHING regop

NOTHING nodes are 1 regop wide. We need 2 regops worth of
space. Which means that we can not safely optimise a sequence
that starts with a NOTHING regop that needs to turn into
a jump trie. We therefore ignore such sequences.

see perl #113770 for details.