Enabling `proc sort` on distributed arrays

[jabraham17]

Currently calling sort on a distributed array will result a warning that twoArrayRadix is not supported on distributed arrays

use BlockDist, Sort;
var a = blockDist.createArray(1..100, int);
sort(a); // warning: twoArrayRadix sort no longer handles distributed arrays. Please use TwoArrayDistributedRadixSort.twoArrayDistributedRadixSort instead (but note that it is not stable)
writeln(a);

The reason sort no longer handles distributed arrays is that previously any program that has use Sort would result in use BlockDist, and the support was removed as a easy fix for that.

We should enable sort on distributed arrays without requiring all programs that use Sort to use BlockDist