* optimization: complicated TYPEP tests are less opaque to the type
propagation pass. (lp#1229340)
* optimization: [N]BUTLAST perform a single pass over the list. (lp#1245697)
* optimization: complicated TYPEP tests are less opaque to the type
propagation pass. (lp#1229340)
* optimization: [N]BUTLAST perform a single pass over the list. (lp#1245697)