Fix issue where setValueCount(0) doesn’t work in the case that we’ve shipped vectors across the wire

[asfimport]

We should be able to call setValueCount() on vectors that have been loaded from external buffers

Reporter: Steven Phillips / @StevenMPhillips
Assignee: Steven Phillips / @StevenMPhillips

_{Note: This issue was originally created as ARROW-789. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Duplicate of ARROW-703

[asfimport]

Wes McKinney / @wesm:
Resolved in 30e03a9

[asfimport]

Todd Farmer / @toddfarmer:
Transitioning issue from Resolved to Closed to based on resolution field value.