Make sparse array standalone iterator iterate over a slice in both branches
Make sparse array standalone iterator iterate over a slice in both branches

We perform better when doing whole array iteration vs. iterating over the
domain and indexing into the array, so iterate over the array in both cases.

CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel,hildeth/chapel