Use a "frozen" instance of EOF in LA and SKIP_TOKEN methods. This allows V8 to better optimize that piece of code as it knows the type of value in the execution branch that is almost never ever entered.
Use a "frozen" instance of EOF in LA and SKIP_TOKEN methods.
This allows V8 to better optimize that piece of code as it knows the type of value in the
execution branch that is almost never ever entered.

part of #248

SAP/chevrotain,SAP/chevrotain,SAP/chevrotain,SAP/chevrotain