Spatial memory layout optimization (for distributed regridding)

[juliasloan25]

Our implementation of distributed regridding requires information exchange of certain source data (see SDI #188) to be able to calculate the correct target data. We want to minimize the amount of data that needs to be sent between processes during this operation. To minimize this transfer, we should maximize the amount of overlap in memory space (and physical space) between corresponding target and source data on each process. This memory layout optimization will involve re-ordering the source and/or target data before the regridding information exchange.

Before implementing this feature, we will have to research the problem (including discussing with Paul Ullrich, Valentin Churavy) and come up with a more concrete approach.