hidden symbols should be seen as local when converting objcaps to symcaps
When converting object capabilities to symbol capabilities, we have to decide on symbol visibility earlier than would normally be the case.
Currently, we treat hidden symbols as global since they still are, but only because we have not yet reduced them. We should treat them as if they were local already.
There is an implementation of this at https://github.com/illumos/illumos-gate/compare/master...richlowe:ld/group-symcaps?expand=1
but I don't plan to go further unless/until I can be sure it's actually the right thing to be doing.
It is possible we should explicitly only do this when reduction is happening (-Breduce or otherwise FLG_OF_PROCRED).