Revert "roll back optimization that behaves *very* badly for LinkedLists"
Revert "roll back optimization that behaves *very* badly for LinkedLists"

This reverts commit e928d2a4de8a1c11642553decda5ea20ce1460db.

unratito/ceylon.language,lucaswerkmeister/ceylon.language,jvasileff/ceylon.language,jvasileff/ceylon.language,ceylon/ceylon.language,ceylon/ceylon.language,unratito/ceylon.language,lucaswerkmeister/ceylon.language