[Java] Provide pointer to Arrow buffer #22378
Description
Introduce pointer to a memory region within an ArrowBuf.
This pointer will be used as the basis for calculating the hash code within a vector, and equality determination.
This data structure can be considered as a "universal value holder".
Reporter: Liya Fan / @liyafan82
Assignee: Liya Fan / @liyafan82
PRs and other links:
Note: This issue was originally created as ARROW-5970. Please see the migration documentation for further details.