NON-APPLICABLE KEYPARTS

Before, the "ranges [...]" part of optimizer trace would include
ranges for keyparts that were not usable by range access. Two
such cases have been found:

WHERE keypart1 < const AND keypart2 ... 
(or any other non-equality operator for keypart1)
  => keypart2 is not applicable for range access because
     the operator on keypart1 is not equality, but optimizer
     tracing would print the range for keypart2 anyway

WHERE keypart1 = const AND keypart3 ...
  => keypart3 is not applicable for range access because
     there are no predicates for keypart2, but optimizer
     tracing would print the range for keypart3 anyway

Both issues are fixed by this CS.