Fix to allow BNF with semantic action and precedence.
Fix to allow BNF with semantic action and precedence.

DmitrySoshnikov/syntax,DmitrySoshnikov/syntax,DmitrySoshnikov/syntax,DmitrySoshnikov/syntax,DmitrySoshnikov/syntax,DmitrySoshnikov/syntax,DmitrySoshnikov/syntax,DmitrySoshnikov/syntax,DmitrySoshnikov/syntax