Precompiled field map permutation and averaging
Provided a pair of functions, MapFieldPermutation and
MapFieldMergeAverage that do the most common operations
for the MapFieldOntoOutput stage of filter execution
(other than doing nothing). These methods are precompiled
into the vtkm_filter library. Although they only use
the default policy (they do not respect custom policies),
they are pre-compiled with all possible types basic types
(up to a Vec size of 4).
Even though the new versions support more field types, the compile time is about the same as before.