Let fetch_unroll_info override the exec_mode and handle rethrowing scopes Scopes with rethrow_exception set to true need to be handled for all types of deoptimization, not just for uncommon traps. This change moves their handling from uncommon_trap_inner to fetch_unroll_info_helper and uses exception_oop and exec_mode Unpack_exception rather than setting a pending execption. fetch_unroll_info_helper can now override the exec_mode by passing it through the UnrollBlock.