track statement comment as instance variable
track statement comment as instance variable

The statement comment was failing to be buffered when using specific FSM
output types from Ragel (one of -F0, -F1, or -T0).

OpenBEL/bel.rb,nbargnesi/bel.rb,nbargnesi/bel.rb,nbargnesi/bel.rb,OpenBEL/bel.rb,nbargnesi/bel.rb,OpenBEL/bel.rb,OpenBEL/bel.rb,nbargnesi/bel.rb,OpenBEL/bel.rb,OpenBEL/bel.rb,OpenBEL/bel.rb,nbargnesi/bel.rb