Internal representation of the lexer's configuration.
(vl-lexstate-p x) is a defaggregate of the following fields.
kwdtable — The set of lex-keywords that are currently supported; this
could be, e.g., the Verilog 2005 keywords or the SystemVerilog
2012 keywords, and might or might not include VL extensions. Invariant (vl-keyword-table-p kwdtable).