ast: adding more convenience for mozilla AST
ast: adding more convenience for mozilla AST

LivelyKernel/LivelyKernel,pascience/LivelyKernel,pascience/LivelyKernel,NikolaySuslov/LivelyKernel,NikolaySuslov/LivelyKernel,LivelyKernel/LivelyKernel,pascience/LivelyKernel,NikolaySuslov/LivelyKernel,LivelyKernel/LivelyKernel