There are quite a few configs that are missing some COMPAT_NN options
in ways that don't make sense; this should probably get cleaned up
too, but for the time being I've not added or removed anything.
replaced by the make option COPY_SYMTAB set to any value. The copy of
the symbol table is no longer put into a buffer in kern_ksyms.o, but a
small helper object. This object is build first with a dummy size, then
the kernel is linked to compute the real dimension of the symbol table
buffer. After that, the helper object is rebuild and the kernel linked
again.
