refactor DFASerializer and LexerDFASerializer to ES6 classes
refactor DFASerializer and LexerDFASerializer to ES6 classes

ericvergnaud/antlr4,antlr/antlr4,parrt/antlr4,parrt/antlr4,antlr/antlr4,parrt/antlr4,antlr/antlr4,parrt/antlr4,parrt/antlr4,parrt/antlr4,parrt/antlr4,antlr/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,antlr/antlr4,parrt/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,parrt/antlr4,ericvergnaud/antlr4,antlr/antlr4,antlr/antlr4,parrt/antlr4,antlr/antlr4,antlr/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,ericvergnaud/antlr4,antlr/antlr4,ericvergnaud/antlr4