Go runtime panic #3929
Description
@chenquan reported bug here: #3834 (comment)
I found this problem in github.com/antlr/antlr4/runtime/Go/antlr v1.4.10. grammar:https://github.com/antlr/grammars-v4/tree/master/sql/mysql/Positive-Technologies
panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext [recovered]
panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext [recovered]
panic: interface conversion: antlr.PredictionContext is *antlr.EmptyPredictionContext, not *antlr.ArrayPredictionContext