[Java] add long map support

[chaokunyang]

Is your feature request related to a problem? Please describe.
Map with long type key using java.util.HashMap will incur boxing cost, a new map implementation is needed.

Describe the solution you'd like
Implement a new map with long[] key array and Object[] value array. Using linear probing and Fibonacci hashing.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
#42