Simplify the code building lists of spans, no output change intended.

Simplify the code building lists of spans, no output change intended.

A comment in the code claimed that the list of spans would be sorted,
but the sorting did not actually work.  The layout "LSSS,LLSL" resulted
in the list "0-3, 1-2", whereas the layout "LLSL,LSSS" resulted
in the list "1-2, 0-3".  Since sorting serves no purpose, just leave
the list unsorted.