The testing files (even the headers) are not available if
`VTKm_ENABLE_TESTING` is off.
Mostly, the testing was used to generate example data sets. Instead,
change the examples to load data files.
A new header named TypeList.h and the type lists have been redefined in
this new file. All the types have been renamed from `TypeListTag*` to
`TypeList*`. TypeListTag.h has been gutted to provide deprecated
versions of the old type list names.
There were also some other type lists that were changed from using the
old `ListTagBase` to the new `List`.
Consumers of VTK-m when enabling of dropping of unused functions
will see VTK-m functions dropped. Previously this didn't happen
as VTK-m didn't build object files with the correct flags for this.
By allowing the linker to remove unused symbols we see a significant
saving the file size of VTK-m tests, examples, and benchmarks.
An OpenMP build of the tests and benchmarks goes from 168MB to
141MB which is roughly a 16% filesize reduction.
Initially I had presumed that these changes would increase link times.
But in measurements the total wall time for compilation of VTK-m has
stayed about the same ( seeing a decrease of 1.5% ). Presumably the
increased computation is offset by the reduction in file writing.
To help provide a better time writing VTK-m filter this streamlines
the CreateResult API to provide a focused set of methods, based on
how CreateResult has been used by existing filters.