Class OrderedMap

A procedure used to represent a FLWOR expression with an {@code order by} clause. (ValuesMap is used for FLWOR expression that don't have an {@code order by} clause.) As returned by the parser:

 for $x1 in exp1, $x2 in exp2 where cond order by comparator1 ... return body
 

is represented as

 ordered-map(tuple-sequence, body-function,
             comparator-function1, flags1, collation1, ...)
 

Here tuple-sequence is an expression that returns a sequence of tuples, which are currently implemnted as Java Object[] arrays. After inlining we get:

 ordered-map(tuple-sequence.
   OrderedTuples.make$V(body-function,
     new Object[]{comparator-function1, flags1, collation1, ...}))
 

A future optimization would be to create an instance of a new sub-class of OrderedTuples. Then the body-function and comparator-functions could be compiled as methods to that class. That wins especially if it saves us having to create extra frame classes.