fix: InteriorPtr doesn't work because rtyper translates it down to Ptr. Therefore iref type translation is done by using hints to opaque type hack.
Added translation support for converting RPython list struct/array to meta-circular array. Implemented compiler intrinsic llops 'mu_meta_barebuf2cstriref' and 'mu_meta_lst2metacarr' in ll2mu.
Small tests for the meta-circular binding seems okay.