@Override
	public boolean resolvesToToken(String x, ActionAST node) {
		if ( tokenRefs.get(x)!=null ) return true;
		LabelElementPair anyLabelDef = getAnyLabelDef(x);
		if ( anyLabelDef!=null && anyLabelDef.type==LabelType.TOKEN_LABEL ) return true;
		return false;
	}
Track all executable actions other than named actions like @init
 and catch/finally (not in an alt). Also tracks predicates, rewrite actions.
 We need to examine these actions before code generation so
 that we can detect refs to $rule.attr etc...

 This tracks per alt
tool/src/org/antlr/v4/tool/Alternative.java