Add ATH_RESTRICT to addBiotSavart inputs.
Add ATH_RESTRICT to addBiotSavart inputs, as they are tagged with it from the function calling it. Also check first if we are inside the r span of a cell BFieldCache::inside
Add ATH_RESTRICT to addBiotSavart inputs, as they are tagged with it from the function calling it. Also check first if we are inside the r span of a cell BFieldCache::inside