Walk each NFA configuration in this DFA state looking for a conflict
where (s|i|ctx) and (s|j|ctx) exist, indicating that state s with
context conflicting ctx predicts alts i and j.
What GrammarAST node (derived from the grammar) is this DFA
associated with? It will point to the start of a block or
the loop back of a (...)+ block etc...
Given a grammar type, what should be the default action scope?
If I say @members in a COMBINED grammar, for example, the
default scope should be "parser".
Return a list of File objects that name files ANTLR will read
to process T.g; for now, this can only be .tokens files and only
if they use the tokenVocab option.
For gated productions, we need an OR'd list of all predicates for the
target of an edge so we can gate the edge based upon the predicates
associated with taking that path (if any).
If a rule has no user-defined return values and nobody references
it's start/stop (predefined attributes), then there is no need to
define a struct; otherwise for now we assume a struct.