Mark some functions as 'inline' to avoid warnings.
Mark some functions as 'inline' to avoid warnings.

Now that we have more instantiation files, not every auxiliary function is used
in every translation unit: get around the warning by marking functions as
inline.

In addition: avoid using an anonymous namespace here, since we use
SPLIT_INSTANTIATIONS_INDEX.

naliboff/dealii,naliboff/dealii,naliboff/dealii,naliboff/dealii,naliboff/dealii,naliboff/dealii,naliboff/dealii